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INTEGRATED CIRCUITS
P83C654X2/P87C654X2 80C51 8-bit microcontroller family
16 kB OTP/ROM, 256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
Product data
Supersedes data of 2003 Feb 13
2004 Apr 20
Philips Semiconductors
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
- Clock can be stopped and resumed - Idle mode - Power-down mode
DESCRIPTION
The devices are Single-Chip 8-Bit Microcontrollers manufactured in an advanced CMOS process and are derivatives of the 80C51 microcontroller family. The instruction set is 100 % compatible with the 80C51 instruction set. The devices support 6-clock/12-clock mode selection by programming an OTP bit (OX2) using parallel programming. In addition, an SFR bit (X2) in the clock control register (CKCON) also selects between 6-clock/12-clock mode. The devices also have four 8-bit I/O ports, three 16-bit timer/event counters, a multi-source, four-priority-level, nested interrupt structure, an enhanced UART and on-chip oscillator and timing circuits. The added features of the P8xC654X2 make it a powerful microcontroller for applications that require pulse width modulation, high-speed I/O and up/down counting capabilities such as motor control.
* CMOS and TTL compatible * Two speed ranges at VCC = 5 V
- 0 to 30 MHz with 6-clock operation - 0 to 33 MHz with 12-clock operation
* Parallel programming with 87C51 compatible hardware interface
to programmer
FEATURES
* 80C51 Central Processing Unit
- 16 kbytes OTP - 256 byte RAM - Boolean processor - Fully static operation - Low voltage (2.7 V to 5.5 V at 16 MHz) operation
* RAM expandable externally to 64 kbytes * PLCC and LQFP packages * Extended temperature ranges * Dual Data Pointers * Security bits (3 bits) * Encryption array - 64 bytes * Seven interrupt sources * Four interrupt priority levels * Four 8-bit I/O ports * Full-duplex enhanced UART
- Framing error detection - Automatic address recognition
* Three 16-bit timers/counters T0, T1 (standard 80C51) and
additional T2 (capture and compare)
* 12-clock operation with selectable 6-clock operation (via software
or via parallel programmer)
* Memory addressing capability
- Up to 64 kbytes ROM and 64 kbytes RAM
* Programmable clock-out pin * Asynchronous port reset * Low EMI (inhibit ALE, slew rate controlled outputs, and 6-clock
mode)
* Power control modes:
* Wake-up from power-down by an external interrupt * Watchdog timer
ORDERING INFORMATION
Type number OTP P83C654X2FA P83C654X2BBD P87C654X2FA P87C654X2BBD - - 16 KB 16 KB ROM 16 KB 16 KB - - RAM 256B 256B 256B 256B Package Name PLCC44 LQFP44 PLCC44 LQFP44 Description plastic leaded chip carrier; 44 leads plastic low profile quad flat package; 44 leads; body 10 10 1.4 mm plastic leaded chip carrier; 44 leads plastic low profile quad flat package; 44 leads; body 10 10 1.4 mm Version SOT187-2 SOT389-1 SOT187-2 SOT389-1 Temp Range (C) -40 to +85 0 to +70 -40 to +85 0 to +70
2004 Apr 20
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Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
BLOCK DIAGRAM 1
ACCELERATED 80C51 CPU (12-CLK MODE, 6-CLK MODE)
16 KB CODE OTP/ROM FULL-DUPLEX ENHANCED UART 256 BYTE DATA RAM TIMER 0 TIMER 1 PORT 3 CONFIGURABLE I/Os TIMER 2 PORT 2 CONFIGURABLE I/Os WATCHDOG TIMER PORT 1 CONFIGURABLE I/Os FAST I2C PORT 0 CONFIGURABLE I/Os
CRYSTAL OR RESONATOR
OSCILLATOR
su01728
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Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
BLOCK DIAGRAM (CPU ORIENTED)
P0.0-P0.7 P2.0-P2.7
PORT 0 DRIVERS VCC VSS RAM ADDR REGISTER RAM PORT 0 LATCH
PORT 2 DRIVERS
PORT 2 LATCH
OTP/ROM MEMORY
8 B REGISTER STACK POINTER
ACC
TMP2
TMP1
PROGRAM ADDRESS REGISTER
ALU SFRs TIMERS PSW P.C.A. 8
BUFFER
PC INCREMENTER 16 PROGRAM COUNTER
PSEN ALE EAVPP RST PD TIMING AND CONTROL
INSTRUCTION REGISTER
DPTR'S MULTIPLE
PORT 1 LATCH
PORT 3 LATCH
OSCILLATOR PORT 1 DRIVERS XTAL1 XTAL2 P1.0-P1.7 PORT 3 DRIVERS
P3.0-P3.7
SU01751
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Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
LOGIC SYMBOL
VCC XTAL1 VSS
Plastic Quad Flat Pack
44 34
1 PORT 0 ADDRESS AND DATA BUS LQFP
33
XTAL2 T2 T2EX SCL0 SDA0 SCL1 SDA1
11
23
RST EA/VPP PSEN SECONDARY FUNCTIONS ALE/PROG RxD TxD INT0 INT1 T0 T1 WR RD
PORT 1
12 Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Function P1.5 P1.6/SCL0 P1.7/SDA0 RST P3.0/RxD VSS32 P3.1/TxD P3.2/INT0 P3.3/INT1 P3.4/T0 P3.5/T1 P3.6/WR P3.7/RD XTAL2 XTAL1 Pin 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Function VSS1 NIC1 P2.0/A8 P2.1/A9 P2.2/A10 P2.3/A11 P2.4/A12 P2.5/A13 P2.6/A14 P2.7/A15 PSEN ALE VSS22 EA/VPP P0.7/AD7
22 Pin 31 32 33 34 35 36 37 38 39 40 41 42 43 44 Function P0.6/AD6 P0.5/AD5 P0.4/AD4 P0.3/AD3 P0.2/AD2 P0.1/AD1 P0.0/AD0 VCC NIC1 P1.0/T2 P1.1/T2EX P1.2/ECI P1.3 P1.4
PORT 3
PORT 2
ADDRESS BUS
SU01730
PINNING Plastic Leaded Chip Carrier
6 1 40
SU01731
1. No internal connection 2. May be left open, but it is recommended that VSS2 and VSS3 be connected to GND to improve EMC performance
39
7
LCC
17
29
18 Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Function NIC1 P1.0/T2 P1.1/T2EX P1.2/ECI P1.3 P1.4 P1.5 P1.6/SCL0 P1.7/SDA0 RST P3.0/RxD VSS32 P3.1/TxD P3.2/INT0 P3.3/INT1 Pin 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Function P3.4/T0 P3.5/T1 P3.6/WR P3.7/RD XTAL2 XTAL1 VSS1 NIC1 P2.0/A8 P2.1/A9 P2.2/A10 P2.3/A11 P2.4/A12 P2.5/A13 P2.6/A14
28 Pin 31 32 33 34 35 36 37 38 39 40 41 42 43 44 Function P2.7/A15 PSEN ALE VSS22 EA/VPP P0.7/AD7 P0.6/AD6 P0.5/AD5 P0.4/AD4 P0.3/AD3 P0.2/AD2 P0.1/AD1 P0.0/AD0 VCC
SU01729
1. No internal connection 2. May be left open, but it is recommended that VSS2 and VSS3 be connected to GND to improve EMC performance
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Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
PIN DESCRIPTIONS
MNEMONIC VSS VCC P0.0-0.72 PIN NUMBER PLCC 22 44 43-36 LQFP 16 38 37-30 I I I/O Ground: 0 V reference. Power Supply: This is the power supply voltage for normal, idle, and power-down operation. Port 0: Port 0 is an open-drain, bidirectional I/O port. Port 0 pins that have 1s written to them float and can be used as high-impedance inputs. Port 0 is also the multiplexed low-order address and data bus during accesses to external program and data memory. In this application, it uses strong internal pull-ups when emitting 1s. Port 1: Port 1 is an 8-bit bidirectional I/O port with internal pull-ups on all pins. Port 1 pins that have 1s written to them are pulled HIGH by the internal pull-ups and can be used as inputs. As inputs, port 1 pins that are externally pulled LOW will source current because of the internal pull-ups. (See DC Electrical Characteristics: IIL). Alternate functions for P8xC654X2 Port 1 include: T2 (P1.0): Timer/Counter 2 external count input/Clockout (see Programmable Clock-Out) T2EX (P1.1): Timer/Counter 2 Reload/Capture/Direction Control TYPE NAME AND FUNCTION
P1.0-P1.72
2-9
40-44, 1-3
I/O
2 3 3 4 5 6 7 8 9 P2.0-P2.72 24-31
40 41 41 42 43 44 1 2 3 18-25
I/O I I I I/O I/O I/O I/O I/O I/O
SCL (P1.6): I2C-bus clock line (open drain) SDA (P1.7): I2C-bus data line (open drain) Port 2: Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. Port 2 pins that have 1s written to them are pulled HIGH by the internal pull-ups and can be used as inputs. As inputs, port 2 pins that are externally being pulled LOW will source current because of the internal pull-ups. (See DC Electrical Characteristics: IIL). Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX @DPTR). In this application, it uses strong internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOV @Ri), port 2 emits the contents of the P2 special function register. Port 3: Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. Port 3 pins that have 1s written to them are pulled HIGH by the internal pull-ups and can be used as inputs. As inputs, port 3 pins that are externally being pulled LOW will source current because of the pull-ups. (See DC Electrical Characteristics: IIL). Port 3 also serves the special features of the P8xC654X2, as listed below: RxD (P3.0): Serial input port TxD (P3.1): Serial output port INT0 (P3.2): External interrupt 0 INT1 (P3.3): External interrupt 1 T0 (P3.4): Timer 0 external input T1 (P3.5): Timer 1 external input WR (P3.6): External data memory write strobe RD (P3.7): External data memory read strobe Reset: A HIGH on this pin for two machine cycles while the oscillator is running, resets the device. An internal diffused resistor to VSS permits a power-on reset using only an external capacitor to VCC. Address Latch Enable: Output pulse for latching the LOW byte of the address during an access to external memory. In normal operation, ALE is emitted at constant rate of 1/6 the oscillator frequency in 12x clock mode, 1/3 the oscillator frequency in 6x clock mode, and can be used for external timing or clocking. Note that one ALE pulse is skipped during each access to external data memory. ALE can be disabled by setting SFR auxiliary.0. With this bit set, ALE will be active only during a MOVX instruction. Program Store Enable: The read strobe to external program memory. When executing code from the external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory. PSEN is not activated during fetches from internal program memory.
P3.0-P3.72
11, 13-19
5, 7-13
I/O
11 13 14 15 16 17 18 19 RST2 10
5 7 8 9 10 11 12 13 4
I O I I I I O O I
ALE2
33
27
O
PSEN2
32
26
O
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Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
MNEMONIC EA2
PIN NUMBER PLCC 35 LQFP 29
TYPE I
NAME AND FUNCTION External Access Enable/Programming Supply Voltage: EA must be externally held LOW to enable the device to fetch code from external program memory. The value on the EA pin is latched when RST is released and any subsequent changes have no effect. Crystal 1: Input to the inverting oscillator amplifier and input to the internal clock generator circuits. Crystal 2: Output from the inverting oscillator amplifier.
XTAL1 XTAL2
21 20
15 14
I O
NOTES: 1. To avoid "latch-up" effect at power-on, the voltage on any pin (other than EA) at any time must not be higher than VCC + 0.5 V or less than VSS - 0.5 V, respectively. 2. The pins are designed for test mode also.
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Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
SPECIAL FUNCTION REGISTERS
SYMBOL ACC* AUXR# AUXR1# B* CKCON DPTR: DPH DPL IEN0* IEN1* IP*# IPH# P0* P1*# P2* P3* PCON#1 PSW* RCAP2H# RCAP2L# SADDR# SADEN# SBUF SCON* SP TCON* T2CON* T2MOD# TH0 TH1 TH2# DESCRIPTION Accumulator Auxiliary Auxiliary 1 B register Clock control Data Pointer (2 bytes) Data Pointer High Data Pointer Low Interrupt Enable 0 Interrupt Enable 1 Interrupt Priority Interrupt Priority High Port 0 Port 1 Port 2 Port 3 Power Control Program Status Word Timer 2 Capture High Timer 2 Capture Low Slave Address Slave Address Mask Serial Data Buffer Serial Control Stack Pointer Timer Control Timer 2 Control Timer 2 Mode Control Timer High 0 Timer High 1 Timer High 2 83H 82H AF A8H E8H B8H B7H 80H 90H A0H B0H 87H D0H CBH CAH A9H B9H 99H 9F 98H 81H 8F 88H C8H C9H 8CH 8DH CDH TF1 CF TF2 - 8E TR1 CE EXF2 - 8D TF0 CD RCLK - 8C TR0 CC TCLK - 8B IE1 CB EXEN2 - 8A IT1 CA TR2 - 89 IE0 C9 C/T2 T2OE 88 IT0 C8 CP/ RL2 DCEN 00H xxxxxx00B 00H 00H 00H 00H
SM0/FE
DIRECT ADDRESS E0H 8EH A2H F0H 8FH
BIT ADDRESS, SYMBOL, OR ALTERNATIVE PORT FUNCTION MSB E7 - - F7 - E6 - - F6 - E5 - - F5 - E4 - LPEP F4 - E3
Fast/STD I2C
LSB E2 - 0 F2 - E1 - - F1 - E0 AO DPS F0 X2
RESET VALUE 00H xxxx1xx0B xxxx00x0B 00H xxxxxxx0B 00H 00H
GPS F3 -
AE EC - BE - B6 PPCH 86 AD6 96 SCL A6 AD14 B6 WR SMOD0 D6 AC
AD ES1 - BD PS1 B5 PS1H 85 AD5 95 - A5 AD13 B5 T1 - D5 F0
AC ES0 - BC PS0 B4 PS0H 84 AD4 94 - A4 AD12 B4 T0 POF D4 RS1
AB ET1 - BB PT1 B3 PT1H 83 AD3 93 - A3 AD11 B3 INT1 GF1 D3 RS0
AA EX1 - BA PX1 B2 PX1H 82 AD2 92 - A2 AD10 B2 INT0 GF0 D2 OV
A9 ET0 ES2 B9 PT0 B1 PT0H 81 AD1 91 T2EX A1 AD9 B1 TxD PD D1 F1
A8 EX0 ET2 B8 PX0 B0 PX0H 80 AD0 90 T2 A0 AD8 B0 RxD IDL D0 P 00000000B 00H 00H 00H 00H xxxxxxxxB FFH 00xx0000B FFH FFH FFH 00000000B 00000000B 00000000B xxxxxx00B
EA - BF PT2 B7 PT2H 87 AD7 97 SDA A7 AD15 B7 RD SMOD1 D7 CY
9E SM1
9D SM2
9C REN
9B TB8
9A RB8
99 TI
98 RI 00H 07H
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Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
SYMBOL TL0 TL1 TL2# TMOD S1CON S1STA S1DAT S1ADR
DESCRIPTION Timer Low 0 Timer Low 1 Timer Low 2 Timer Mode I2C Control I2C STATUS I2C DATA I2C ADDRESS
DIRECT ADDRESS 8AH 8BH CCH 89H D8H D9H DAH DBH
BIT ADDRESS, SYMBOL, OR ALTERNATIVE PORT FUNCTION MSB LSB
RESET VALUE 00H 00H 00H
GATE CR2 SC4
C/T ENA1 SC3
M1 STA SC2
M0 STO SC1
GATE SI SC0
C/T AA 0
M1 CR1 0
M0 CR0 0 GC
00H 00H F8H 00H 00H
WDTRST Watchdog Reset Timer A6H * SFRs are bit addressable. # SFRs are modified from or added to the 80C51 SFRs. - Reserved bits. 1. Reset value depends on reset source.
2004 Apr 20
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Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
CLOCK CONTROL REGISTER (CKCON)
This device allows control of the 6-clock/12-clock mode by means of both an SFR bit (X2) and an OTP bit. The OTP clock control bit
OX2, when programmed (6-clock mode), supersedes the X2 bit (CKCON.0). The CKCON register is shown below in Figure 1.
CKCON
Address = 8Fh Not Bit Addressable
Reset Value = x0000000B
7 - BIT CKCON.7 CKCON.6 CKCON.5 CKCON.4 CKCON.3 CKCON.2 CKCON.1 CKCON.0 SYMBOL -
6 -
5 -
4 -
3 -
2 -
1 -
0 X2
X2
FUNCTION Reserved. Reserved. Reserved. Reserved. Reserved. Reserved. Reserved. CPU clock; 1 = 6 clocks for each machine cycle, 0 = 12 clocks for each machine cycle
SU01689
Figure 1. Clock control (CKCON) register Also please note that the clock divider applies to the serial port for modes 0 and 2 (fixed baud rate modes). This is because modes 1 and 3 (variable baud rate modes) use either Timer 1 or Timer 2. Below is the truth table for the CPU clock mode.
Table 1.
OX2 clock mode bit (can only be set by parallel programmer) erased erased programmed X2 bit (CKCON.0) 0 1 X CPU clock mode
12-clock mode (default) 6-clock mode 6-clock mode
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Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
OSCILLATOR CHARACTERISTICS
XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier. The pins can be configured for use as an on-chip oscillator. To drive the device from an external clock source, XTAL1 should be driven while XTAL2 is left unconnected. Minimum and maximum high and low times specified in the data sheet must be observed. This device is configured at the factory to operate using 12 clock periods per machine cycle, referred to in this datasheet as "12-clock mode". It may be optionally configured on commercially available EPROM programming equipment to operate at 6 clocks per machine cycle, referred to in this datasheet as "6-clock mode". (This yields performance equivalent to twice that of standard 80C51 family devices). Also see next page. To properly terminate power-down, the reset or external interrupt should not be executed before VCC is restored to its normal operating level and must be held active long enough for the oscillator to restart and stabilize (normally less than 10 ms). With an external interrupt, INT0 and INT1 must be enabled and configured as level-sensitive. Holding the pin LOW restarts the oscillator but bringing the pin back HIGH completes the exit. Once the interrupt is serviced, the next instruction to be executed after RETI will be the one following the instruction that put the device into power-down.
POWER-OFF FLAG
The Power-Off Flag (POF) is set by on-chip circuitry when the VCC level on the P8xC654X2 rises from 0 to 5 V. The POF bit can be set or cleared by software allowing a user to determine if the reset is the result of a power-on or a warm start after power-down. The VCC level must remain above 3 V for the POF to remain unaffected by the VCC level.
RESET
A reset is accomplished by holding the RST pin HIGH for at least two machine cycles (12 oscillator periods in 6-clock mode, or 24 oscillator periods in 12-clock mode), while the oscillator is running. To insure a good power-on reset, the RST pin must be HIGH long enough to allow the oscillator time to start up (normally a few milliseconds) plus two machine cycles. At power-on, the voltage on VCC and RST must come up at the same time for a proper start-up. Ports 1, 2, and 3 will asynchronously be driven to their reset condition when a voltage above VIH (min.) is applied to RESET. The value on the EA pin is latched when RST is deasserted and has no further effect.
Low-Power EPROM operation (LPEP)
The EPROM array contains some analog circuits that are not required when VCC is less than 4 V, but are required for a VCC greater than 4 V. The LPEP bit (AUXR.4), when set, will power-down these analog circuits resulting in a reduced supply current. This bit should be set ONLY for applications that operate at a VCC less than 4 V.
Design Consideration
When the idle mode is terminated by a hardware reset, the device normally resumes program execution, from where it left off, up to two machine cycles before the internal reset algorithm takes control. On-chip hardware inhibits access to internal RAM in this event, but access to the port pins is not inhibited. To eliminate the possibility of an unexpected write when Idle is terminated by reset, the instruction following the one that invokes Idle should not be one that writes to a port pin or to external memory.
LOW POWER MODES Stop Clock Mode
The static design enables the clock speed to be reduced down to 0 MHz (stopped). When the oscillator is stopped, the RAM and Special Function Registers retain their values. This mode allows step-by-step utilization and permits reduced system power consumption by lowering the clock frequency down to any value. For lowest power consumption the Power-down mode is suggested.
ONCETM Mode
The ONCE ("On-Circuit Emulation") Mode facilitates testing and debugging of systems without the device having to be removed from the circuit. The ONCE Mode is invoked by: 1. Pull ALE LOW while the device is in reset and PSEN is HIGH; 2. Hold ALE LOW as RST is deactivated. While the device is in ONCE Mode, the Port 0 pins go into a float state, and the other port pins and ALE and PSEN are weakly pulled HIGH. The oscillator circuit remains active. While the device is in this mode, an emulator or test CPU can be used to drive the circuit. Normal operation is restored when a normal reset is applied.
Idle Mode
In the idle mode (see Table 2), the CPU puts itself to sleep while all of the on-chip peripherals stay active. The instruction to invoke the idle mode is the last instruction executed in the normal operating mode before the idle mode is activated. The CPU contents, the on-chip RAM, and all of the special function registers remain intact during this mode. The idle mode can be terminated either by any enabled interrupt (at which time the process is picked up at the interrupt service routine and continued), or by a hardware reset which starts the processor in the same manner as a power-on reset.
Power-Down Mode
To save even more power, a Power-down mode (see Table 2) can be invoked by software. In this mode, the oscillator is stopped and the instruction that invoked power-down is the last instruction executed. The on-chip RAM and Special Function Registers retain their values down to 2 V and care must be taken to return VCC to the minimum specified operating voltages before the Power-down mode is terminated. Either a hardware reset or external interrupt can be used to exit from power-down. Reset redefines all the SFRs but does not change the on-chip RAM. An external interrupt allows both the SFRs and the on-chip RAM to retain their values.
Programmable Clock-Out
A 50 % duty cycle clock can be programmed to come out on P1.0. This pin, besides being a regular I/O pin, has two alternate functions. It can be programmed: 1. to input the external clock for Timer/Counter 2, or 2. to output a 50 % duty cycle clock ranging from 122 Hz to 8 MHz at a 16 MHz operating frequency (61 Hz to 4 MHz in 12-clock mode). To configure the Timer/Counter 2 as a clock generator, bit C/T2 (in T2CON) must be cleared and bit T20E in T2MOD must be set. Bit TR2 (T2CON.2) also must be set to start the timer.
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Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
The Clock-Out frequency depends on the oscillator frequency and the reload value of Timer 2 capture registers (RCAP2H, RCAP2L) as shown in this equation: n n= Oscillator Frequency (65536 * RCAP2H, RCAP2L) 2 in 6-clock mode 4 in 12-clock mode
Where (RCAP2H,RCAP2L) = the content of RCAP2H and RCAP2L taken as a 16-bit unsigned integer. In the Clock-Out mode Timer 2 roll-overs will not generate an interrupt. This is similar to when it is used as a baud-rate generator. It is possible to use Timer 2 as a baud-rate generator and a clock generator simultaneously. Note, however, that the baud-rate and the Clock-Out frequency will be the same.
Table 2. External Pin Status During Idle and Power-Down Mode
MODE Idle Idle Power-down Power-down PROGRAM MEMORY Internal External Internal External ALE 1 1 0 0 PSEN 1 1 0 0 PORT 0 Data Float Data Float PORT 1 Data Data Data Data PORT 2 Data Address Data Data PORT 3 Data Data Data Data
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Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
TIMER 0 AND TIMER 1 OPERATION Timer 0 and Timer 1
The "Timer" or "Counter" function is selected by control bits C/T in the Special Function Register TMOD. These two Timer/Counters have four operating modes, which are selected by bit-pairs (M1, M0) in TMOD. Modes 0, 1, and 2 are the same for both Timers/Counters. Mode 3 is different. The four operating modes are described in the following text. Mode 0 Putting either Timer into Mode 0 makes it look like an 8048 Timer, which is an 8-bit Counter with a divide-by-32 prescaler. Figure 3 shows the Mode 0 operation. In this mode, the Timer register is configured as a 13-bit register. As the count rolls over from all 1s to all 0s, it sets the Timer interrupt flag TFn. The counted input is enabled to the Timer when TRn = 1 and either GATE = 0 or INTn = 1. (Setting GATE = 1 allows the Timer to be controlled by external input INTn, to facilitate pulse width measurements). TRn is a control bit in the Special Function Register TCON (Figure 4). The 13-bit register consists of all 8 bits of THn and the lower 5 bits of TLn. The upper 3 bits of TLn are indeterminate and should be ignored. Setting the run flag (TRn) does not clear the registers. Mode 0 operation is the same for Timer 0 as for Timer 1. There are two different GATE bits, one for Timer 1 (TMOD.7) and one for Timer 0 (TMOD.3).
Mode 1 Mode 1 is the same as Mode 0, except that the Timer register is being run with all 16 bits. Mode 2 Mode 2 configures the Timer register as an 8-bit Counter (TLn) with automatic reload, as shown in Figure 5. Overflow from TLn not only sets TFn, but also reloads TLn with the contents of THn, which is preset by software. The reload leaves THn unchanged. Mode 2 operation is the same for Timer 0 as for Timer 1. Mode 3 Timer 1 in Mode 3 simply holds its count. The effect is the same as setting TR1 = 0. Timer 0 in Mode 3 establishes TL0 and TH0 as two separate counters. The logic for Mode 3 on Timer 0 is shown in Figure 6. TL0 uses the Timer 0 control bits: C/T, GATE, TR0, and TF0 as well as pin INT0. TH0 is locked into a timer function (counting machine cycles) and takes over the use of TR1 and TF1 from Timer 1. Thus, TH0 now controls the "Timer 1" interrupt. Mode 3 is provided for applications requiring an extra 8-bit timer on the counter. With Timer 0 in Mode 3, an 80C51 can look like it has three Timer/Counters. When Timer 0 is in Mode 3, Timer 1 can be turned on and off by switching it out of and into its own Mode 3, or can still be used by the serial port as a baud rate generator, or in fact, in any application not requiring an interrupt. Reset Value = 00H
TMOD
Address = 89H Not Bit Addressable 7 GATE 6 C/T 5 M1 4 M0 3 GATE 2 C/T 1 M1 0
M0
TIMER 1 BIT TMOD.3/ TMOD.7 TMOD.2/ TMOD.6 SYMBOL GATE C/T M1 0 0 1 1 1 M0 0 1 0 1 1
TIMER 0
FUNCTION Gating control when set. Timer/Counter "n" is enabled only while "INTn" pin is high and "TRn" control pin is set. when cleared Timer "n" is enabled whenever "TRn" control bit is set. Timer or Counter Selector cleared for Timer operation (input from internal system clock.) Set for Counter operation (input from "Tn" input pin). OPERATING 8048 Timer: "TLn" serves as 5-bit prescaler. 16-bit Timer/Counter: "THn" and "TLn" are cascaded; there is no prescaler. 8-bit auto-reload Timer/Counter: "THn" holds a value which is to be reloaded into "TLn" each time it overflows. (Timer 0) TL0 is an 8-bit Timer/Counter controlled by the standard Timer 0 control bits. TH0 is an 8-bit timer only controlled by Timer 1 control bits. (Timer 1) Timer/Counter 1 stopped.
SU01580
Figure 2. Timer/Counter 0/1 Mode Control (TMOD) Register
2004 Apr 20
13
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
OSC
/ d* C/T = 0 C/T = 1 Tn Pin TRn Control TLn (5 Bits) THn (8 Bits)
TFn
Interrupt
Timer n Gate bit INTn Pin *d = 6 in 6-clock mode; d = 12 in 12-clock mode.
SU01618
Figure 3. Timer/Counter 0/1 Mode 0: 13-Bit Timer/Counter
TCON
Address = 88H Bit Addressable
Reset Value = 00H
7 TF1 BIT TCON.7 TCON.6 TCON.5 TCON.4 TCON.3 TCON.2 TCON.1 TCON.0 SYMBOL TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0
6 TR1
5 TF0
4 TR0
3 IE1
2 IT1
1 IE0
0 IT0
FUNCTION Timer 1 overflow flag. Set by hardware on Timer/Counter overflow. Cleared by hardware when processor vectors to interrupt routine, or clearing the bit in software. Timer 1 Run control bit. Set/cleared by software to turn Timer/Counter on/off. Timer 0 overflow flag. Set by hardware on Timer/Counter overflow. Cleared by hardware when processor vectors to interrupt routine, or by clearing the bit in software. Timer 0 Run control bit. Set/cleared by software to turn Timer/Counter on/off. Interrupt 1 Edge flag. Set by hardware when external interrupt edge detected. Cleared when interrupt processed. Interrupt 1 type control bit. Set/cleared by software to specify falling edge/low level triggered external interrupts. Interrupt 0 Edge flag. Set by hardware when external interrupt edge detected. Cleared when interrupt processed. Interrupt 0 Type control bit. Set/cleared by software to specify falling edge/low level triggered external interrupts.
SU01516
Figure 4. Timer/Counter 0/1 Control (TCON) Register
2004 Apr 20
14
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
OSC
/ d* C/T = 0 TLn (8 Bits) C/T = 1 Tn Pin Control TFn Interrupt
TRn Timer n Gate bit THn (8 Bits) INTn Pin *d = 6 in 6-clock mode; d = 12 in 12-clock mode.
Reload
SU01619
Figure 5. Timer/Counter 0/1 Mode 2: 8-Bit Auto-Reload
OSC
/ d* C/T = 0 TL0 (8 Bits) C/T = 1 T0 Pin Control TF0 Interrupt
TR0 Timer 0 Gate bit INT0 Pin
OSC
/ d* Control TR1
TH0 (8 Bits)
TF1
Interrupt
*d = 6 in 6-clock mode; d = 12 in 12-clock mode.
SU01620
Figure 6. Timer/Counter 0 Mode 3: Two 8-Bit Counters
2004 Apr 20
15
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
TIMER 2 OPERATION Timer 2
Timer 2 is a 16-bit Timer/Counter which can operate as either an event timer or an event counter, as selected by C/T2 in the special function register T2CON (see Figure 7). Timer 2 has three operating modes: Capture, Auto-reload (up or down counting), and Baud Rate Generator, which are selected by bits in the T2CON as shown in Table 3.
Counter Enable) which is located in the T2MOD register (see Figure 9). When reset is applied the DCEN = 0 which means Timer 2 will default to counting up. If DCEN bit is set, Timer 2 can count up or down depending on the value of the T2EX pin. Figure 10 shows Timer 2 which will count up automatically since DCEN = 0. In this mode there are two options selected by bit EXEN2 in T2CON register. If EXEN2 = 0, then Timer 2 counts up to 0FFFFH and sets the TF2 (Overflow Flag) bit upon overflow. This causes the Timer 2 registers to be reloaded with the 16-bit value in RCAP2L and RCAP2H. The values in RCAP2L and RCAP2H are preset by software means. If EXEN2 = 1, then a 16-bit reload can be triggered either by an overflow or by a 1-to-0 transition at input T2EX. This transition also sets the EXF2 bit. The Timer 2 interrupt, if enabled, can be generated when either TF2 or EXF2 are 1. In Figure 11 DCEN = 1 which enables Timer 2 to count up or down. This mode allows pin T2EX to control the direction of count. When a logic 1 is applied at pin T2EX Timer 2 will count up. Timer 2 will overflow at 0FFFFH and set the TF2 flag, which can then generate an interrupt, if the interrupt is enabled. This timer overflow also causes the 16-bit value in RCAP2L and RCAP2H to be reloaded into the timer registers TL2 and TH2. When a logic 0 is applied at pin T2EX this causes Timer 2 to count down. The timer will underflow when TL2 and TH2 become equal to the value stored in RCAP2L and RCAP2H. Timer 2 underflow sets the TF2 flag and causes 0FFFFH to be reloaded into the timer registers TL2 and TH2. The external flag EXF2 toggles when Timer 2 underflows or overflows. This EXF2 bit can be used as a 17th bit of resolution if needed. The EXF2 flag does not generate an interrupt in this mode of operation.
Capture Mode
In the capture mode there are two options which are selected by bit EXEN2 in T2CON. If EXEN2 = 0, then timer 2 is a 16-bit timer or counter (as selected by C/T2 in T2CON) which, upon overflowing sets bit TF2, the timer 2 overflow bit. This bit can be used to generate an interrupt (by enabling the Timer 2 interrupt bit in the IE register). If EXEN2 = 1, Timer 2 operates as described above, but with the added feature that a 1- to -0 transition at external input T2EX causes the current value in the Timer 2 registers, TL2 and TH2, to be captured into registers RCAP2L and RCAP2H, respectively. In addition, the transition at T2EX causes bit EXF2 in T2CON to be set, and EXF2 like TF2 can generate an interrupt (which vectors to the same location as Timer 2 overflow interrupt. The Timer 2 interrupt service routine can interrogate TF2 and EXF2 to determine which event caused the interrupt). The capture mode is illustrated in Figure 8 (There is no reload value for TL2 and TH2 in this mode. Even when a capture event occurs from T2EX, the counter keeps on counting T2EX pin transitions or osc/6 pulses (osc/12 in 12-clock mode).).
Auto-Reload Mode (Up or Down Counter)
In the 16-bit auto-reload mode, Timer 2 can be configured (as either a timer or counter [C/T2 in T2CON]) then programmed to count up or down. The counting direction is determined by bit DCEN (Down
(MSB) TF2 Symbol TF2 EXF2 Position T2CON.7 T2CON.6 EXF2 RCLK TCLK EXEN2 TR2 C/T2
(LSB) CP/RL2
Name and Significance Timer 2 overflow flag set by a Timer 2 overflow and must be cleared by software. TF2 will not be set when either RCLK or TCLK = 1. Timer 2 external flag set when either a capture or reload is caused by a negative transition on T2EX and EXEN2 = 1. When Timer 2 interrupt is enabled, EXF2 = 1 will cause the CPU to vector to the Timer 2 interrupt routine. EXF2 must be cleared by software. EXF2 does not cause an interrupt in up/down counter mode (DCEN = 1). Receive clock flag. When set, causes the serial port to use Timer 2 overflow pulses for its receive clock in modes 1 and 3. RCLK = 0 causes Timer 1 overflow to be used for the receive clock. Transmit clock flag. When set, causes the serial port to use Timer 2 overflow pulses for its transmit clock in modes 1 and 3. TCLK = 0 causes Timer 1 overflows to be used for the transmit clock. Timer 2 external enable flag. When set, allows a capture or reload to occur as a result of a negative transition on T2EX if Timer 2 is not being used to clock the serial port. EXEN2 = 0 causes Timer 2 to ignore events at T2EX. Start/stop control for Timer 2. A logic 1 starts the timer. Timer or counter select. (Timer 2) 0 = Internal timer (OSC/6 in 6-clock mode or OSC/12 in 12-clock mode) 1 = External event counter (falling edge triggered). Capture/Reload flag. When set, captures will occur on negative transitions at T2EX if EXEN2 = 1. When cleared, auto-reloads will occur either with Timer 2 overflows or negative transitions at T2EX when EXEN2 = 1. When either RCLK = 1 or TCLK = 1, this bit is ignored and the timer is forced to auto-reload on Timer 2 overflow. SU01251 Figure 7. Timer/Counter 2 (T2CON) Control Register
RCLK TCLK EXEN2
T2CON.5 T2CON.4 T2CON.3
TR2 C/T2
T2CON.2 T2CON.1
CP/RL2
T2CON.0
2004 Apr 20
16
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Table 3. Timer 2 Operating Modes
RCLK + TCLK 0 0 1 X CP/RL2 0 1 X X TR2 1 1 1 0 16-bit Auto-reload 16-bit Capture Baud rate generator (off) MODE
OSC
/ n*
C/T2 = 0 TL2 (8 BITS) C/T2 = 1 TH2 (8 BITS) TF2
T2 Pin
Control
TR2 Transition Detector
Capture Timer 2 Interrupt RCAP2L RCAP2H
T2EX Pin
EXF2
Control
EXEN2
SU01252
* n = 6 in 6-clock mode, or 12 in 12-clock mode. Figure 8. Timer 2 in Capture Mode
T2MOD
Address = 0C9H Not Bit Addressable -- Bit 7 -- 6 -- 5 -- 4 -- 3 -- 2 T2OE 1
Reset Value = XXXX XX00B
DCEN 0
Symbol -- T2OE DCEN *
Function Not implemented, reserved for future use.* Timer 2 Output Enable bit. Down Count Enable bit. When set, this allows Timer 2 to be configured as an up/down counter.
User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features. In that case, the reset or inactive value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate. Figure 9. Timer 2 Mode (T2MOD) Control Register
SU00729
2004 Apr 20
17
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
OSC
/ n*
C/T2 = 0 TL2 (8 BITS) C/T2 = 1 TH2 (8 BITS)
T2 PIN
CONTROL
TR2
RELOAD
TRANSITION DETECTOR
RCAP2L
RCAP2H TF2 TIMER 2 INTERRUPT
T2EX PIN
EXF2
CONTROL
EXEN2
SU01253
* n = 6 in 6-clock mode, or 12 in 12-clock mode. Figure 10. Timer 2 in Auto-Reload Mode (DCEN = 0)
(DOWN COUNTING RELOAD VALUE) FFH FFH
TOGGLE EXF2
OSC
/ n*
C/T2 = 0 OVERFLOW TL2 TH2 TF2 INTERRUPT
T2 PIN
C/T2 = 1 CONTROL TR2 COUNT DIRECTION 1 = UP 0 = DOWN RCAP2L RCAP2H T2EX PIN
(UP COUNTING RELOAD VALUE)
* n = 6 in 6-clock mode, or 12 in 12-clock mode. Figure 11. Timer 2 Auto Reload Mode (DCEN = 1)
SU01254
2004 Apr 20
18
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Timer 1 Overflow
n = 1 in 6-clock mode n = 2 in 12-clock mode
/2
"0" C/T2 = 0 TL2 (8-bits) C/T2 = 1 TH2 (8-bits) "1" "0" RCLK "1" SMOD
OSC
/n
T2 Pin
Control "1" Reload "0"
/ 16
RX Clock
TR2
TCLK
Transition Detector
RCAP2L
RCAP2H
/ 16
TX Clock
T2EX Pin
EXF2
Timer 2 Interrupt
Control EXEN2 Note availability of additional external interrupt.
SU01629
Figure 12. Timer 2 in Baud Rate Generator Mode
Table 4.
Timer 2 Generated Commonly Used Baud Rates
Timer 2 Osc Freq RCAP2H 12 MHz 12 MHz 12 MHz 12 MHz 12 MHz 12 MHz 12 MHz 6 MHz 6 MHz FF FF FF FF FE FB F2 FD F9 RCAP2L FF D9 B2 64 C8 1E AF 8F 57 6-clock mode 750 k 19.2 k 9.6 k 4.8 k 2.4 k 600 220 600 220
The baud rates in modes 1 and 3 are determined by Timer 2's overflow rate given below: Modes 1 and 3 Baud Rates + Timer 2 Overflow Rate 16 The timer can be configured for either "timer" or "counter" operation. In many applications, it is configured for "timer" operation (C/T2 = 0). Timer operation is different for Timer 2 when it is being used as a baud rate generator. Usually, as a timer it would increment every machine cycle (i.e., 1/ the oscillator frequency in 6-clock mode, 1/ the oscillator 6 12 frequency in 12-clock mode). As a baud rate generator, it increments at the oscillator frequency in 6-clock mode (OSC/2 in 12-clock mode). Thus the baud rate formula is as follows: Modes 1 and 3 Baud Rates = Oscillator Frequency [ n * [65536 * (RCAP2H, RCAP2L)]] *n= 16 in 6-clock mode 32 in 12-clock mode
Baud Rate 12-clock mode 375 k 9.6 k 4.8 k 2.4 k 1.2 k 300 110 300 110
Baud Rate Generator Mode
Bits TCLK and/or RCLK in T2CON (Table 4) allow the serial port transmit and receive baud rates to be derived from either Timer 1 or Timer 2. When TCLK = 0, Timer 1 is used as the serial port transmit baud rate generator. When TCLK = 1, Timer 2 is used as the serial port transmit baud rate generator. RCLK has the same effect for the serial port receive baud rate. With these two bits, the serial port can have different receive and transmit baud rates - one generated by Timer 1, the other by Timer 2. Figure 12 shows the Timer 2 in baud rate generation mode. The baud rate generation mode is like the auto-reload mode,in that a rollover in TH2 causes the Timer 2 registers to be reloaded with the 16-bit value in registers RCAP2H and RCAP2L, which are preset by software.
Where: (RCAP2H, RCAP2L)= The content of RCAP2H and RCAP2L taken as a 16-bit unsigned integer. The Timer 2 as a baud rate generator mode shown in Figure 12, is valid only if RCLK and/or TCLK = 1 in T2CON register. Note that a rollover in TH2 does not set TF2, and will not generate an interrupt. Thus, the Timer 2 interrupt does not have to be disabled when Timer 2 is in the baud rate generator mode. Also if the EXEN2 (T2 external enable flag) is set, a 1-to-0 transition in T2EX (Timer/counter 2 trigger input) will set EXF2 (T2 external flag) but will not cause a reload from (RCAP2H, RCAP2L) to (TH2,TL2). Therefore when Timer 2 is in use as a baud rate generator, T2EX can be used as an additional external interrupt, if needed.
2004 Apr 20
19
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
When Timer 2 is in the baud rate generator mode, one should not try to read or write TH2 and TL2. As a baud rate generator, Timer 2 is incremented every state time (osc/2) or asynchronously from pin T2; under these conditions, a read or write of TH2 or TL2 may not be accurate. The RCAP2 registers may be read, but should not be written to, because a write might overlap a reload and cause write and/or reload errors. The timer should be turned off (clear TR2) before accessing the Timer 2 or RCAP2 registers. Table 4 shows commonly used baud rates and how they can be obtained from Timer 2.
If Timer 2 is being clocked internally, the baud rate is: Baud Rate + f OSC [65536 * (RCAP2H, RCAP2L)]] 16 in 6-clock mode 32 in 12-clock mode
[ n* *n=
Where fosc = Oscillator Frequency To obtain the reload value for RCAP2H and RCAP2L, the above equation can be rewritten as: RCAP2H, RCAP2L + 65536 * f OSC Baud Rate
Summary of Baud Rate Equations
Timer 2 is in baud rate generating mode. If Timer 2 is being clocked through pin T2 (P1.0) the baud rate is: Baud Rate + Timer 2 Overflow Rate 16
n*
Timer/Counter 2 Set-up
Except for the baud rate generator mode, the values given for T2CON do not include the setting of the TR2 bit. Therefore, bit TR2 must be set, separately, to turn the timer on. see Table 5 for set-up of Timer 2 as a timer. Also see Table 6 for set-up of Timer 2 as a counter.
Table 5.
Timer 2 as a Timer
T2CON MODE INTERNAL CONTROL (Note 1) 00H 01H 34H 24H 14H EXTERNAL CONTROL (Note 2) 08H 09H 36H 26H 16H
16-bit Auto-Reload 16-bit Capture Baud rate generator receive and transmit same baud rate Receive only Transmit only
Table 6.
Timer 2 as a Counter
TMOD MODE INTERNAL CONTROL (Note 1) 02H 03H EXTERNAL CONTROL (Note 2) 0AH 0BH
16-bit Auto-Reload
NOTES: 1. Capture/reload occurs only on timer/counter overflow. 2. Capture/reload occurs on timer/counter overflow and a 1-to-0 transition on T2EX (P1.1) pin except when Timer 2 is used in the baud rate generator mode.
2004 Apr 20
20
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
FULL-DUPLEX ENHANCED UART Standard UART operation
The serial port is full duplex, meaning it can transmit and receive simultaneously. It is also receive-buffered, meaning it can commence reception of a second byte before a previously received byte has been read from the register. (However, if the first byte still hasn't been read by the time reception of the second byte is complete, one of the bytes will be lost.) The serial port receive and transmit registers are both accessed at Special Function Register SBUF. Writing to SBUF loads the transmit register, and reading SBUF accesses a physically separate receive register. The serial port can operate in 4 modes: Mode 0: Serial data enters and exits through RxD. TxD outputs the shift clock. 8 bits are transmitted/received (LSB first). The baud rate is fixed at 1/12 the oscillator frequency in 12-clock mode or 1/6 the oscillator frequency in 6-clock mode. 10 bits are transmitted (through TxD) or received (through RxD): a start bit (0), 8 data bits (LSB first), and a stop bit (1). On receive, the stop bit goes into RB8 in Special Function Register SCON. The baud rate is variable. 11 bits are transmitted (through TxD) or received (through RxD): start bit (0), 8 data bits (LSB first), a programmable 9th data bit, and a stop bit (1). On Transmit, the 9th data bit (TB8 in SCON) can be assigned the value of 0 or 1. Or, for example, the parity bit (P, in the PSW) could be moved into TB8. On receive, the 9th data bit goes into RB8 in Special Function Register SCON, while the stop bit is ignored. The baud rate is programmable to either 1/32 or 1/64 the oscillator frequency in 12-clock mode or 1/16 or 1/32 the oscillator frequency in 6-clock mode. 11 bits are transmitted (through TxD) or received (through RxD): a start bit (0), 8 data bits (LSB first), a programmable 9th data bit, and a stop bit (1). In fact, Mode 3 is the same as Mode 2 in all respects except baud rate. The baud rate in Mode 3 is variable.
The slaves that weren't being addressed leave their SM2s set and go on about their business, ignoring the coming data bytes. SM2 has no effect in Mode 0, and in Mode 1 can be used to check the validity of the stop bit. In a Mode 1 reception, if SM2 = 1, the receive interrupt will not be activated unless a valid stop bit is received. Serial Port Control Register The serial port control and status register is the Special Function Register SCON, shown in Figure 13. This register contains not only the mode selection bits, but also the 9th data bit for transmit and receive (TB8 and RB8), and the serial port interrupt bits (TI and RI). Baud Rates The baud rate in Mode 0 is fixed: Mode 0 Baud Rate = Oscillator Frequency / 12 (12-clock mode) or / 6 (6-clock mode). The baud rate in Mode 2 depends on the value of bit SMOD in Special Function Register PCON. If SMOD = 0 (which is the value on reset), and the port pins in 12-clock mode, the baud rate is 1/64 the oscillator frequency. If SMOD = 1, the baud rate is 1/32 the oscillator frequency. In 6-clock mode, the baud rate is 1/32 or 1/16 the oscillator frequency, respectively. Mode 2 Baud Rate = 2 SMOD n Where: n = 64 in 12-clock mode, 32 in 6-clock mode The baud rates in Modes 1 and 3 are determined by the Timer 1 or Timer 2 overflow rate. Using Timer 1 to Generate Baud Rates When Timer 1 is used as the baud rate generator (T2CON.RCLK = 0, T2CON.TCLK = 0), the baud rates in Modes 1 and 3 are determined by the Timer 1 overflow rate and the value of SMOD as follows: Mode 1, 3 Baud Rate = 2 SMOD n Where: n = 32 in 12-clock mode, 16 in 6-clock mode The Timer 1 interrupt should be disabled in this application. The Timer itself can be configured for either "timer" or "counter" operation, and in any of its 3 running modes. In the most typical applications, it is configured for "timer" operation, in the auto-reload mode (high nibble of TMOD = 0010B). In that case the baud rate is given by the formula: Mode 1, 3 Baud Rate = 2 SMOD n Where: n = 32 in 12-clock mode, 16 in 6-clock mode One can achieve very low baud rates with Timer 1 by leaving the Timer 1 interrupt enabled, and configuring the Timer to run as a 16-bit timer (high nibble of TMOD = 0001B), and using the Timer 1 interrupt to do a 16-bit software reload. Figure 14 lists various commonly used baud rates and how they can be obtained from Timer 1. Oscillator Frequency 12 [256-(TH1)] (Timer 1 Overflow Rate) (Oscillator Frequency)
Mode 1:
Mode 2:
Mode 3:
In all four modes, transmission is initiated by any instruction that uses SBUF as a destination register. Reception is initiated in Mode 0 by the condition RI = 0 and REN = 1. Reception is initiated in the other modes by the incoming start bit if REN = 1. Multiprocessor Communications Modes 2 and 3 have a special provision for multiprocessor communications. In these modes, 9 data bits are received. The 9th one goes into RB8. Then comes a stop bit. The port can be programmed such that when the stop bit is received, the serial port interrupt will be activated only if RB8 = 1. This feature is enabled by setting bit SM2 in SCON. A way to use this feature in multiprocessor systems is as follows: When the master processor wants to transmit a block of data to one of several slaves, it first sends out an address byte which identifies the target slave. An address byte differs from a data byte in that the 9th bit is 1 in an address byte and 0 in a data byte. With SM2 = 1, no slave will be interrupted by a data byte. An address byte, however, will interrupt all slaves, so that each slave can examine the received byte and see if it is being addressed. The addressed slave will clear its SM2 bit and prepare to receive the data bytes that will be coming.
2004 Apr 20
21
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
SCON
Address = 98H Bit Addressable
Reset Value = 00H 7 SM0 6 SM1 5 SM2 4 REN 3 TB8 2 RB8 1 TI 0 RI
Where SM0, SM1 specify the serial port mode, as follows: SM0 0 0 1 1 SM2 SM1 0 1 0 1 Mode 0 1 2 3 Description shift register 8-bit UART 9-bit UART 9-bit UART Baud Rate fOSC/12 (12-clock mode) or fOSC/6 (6-clock mode) variable fOSC/64 or fOSC/32 (12-clock mode) or fOSC/32 or fOSC/16 (6-clock mode) variable
Enables the multiprocessor communication feature in Modes 2 and 3. In Mode 2 or 3, if SM2 is set to 1, then Rl will not be activated if the received 9th data bit (RB8) is 0. In Mode 1, if SM2=1 then RI will not be activated if a valid stop bit was not received. In Mode 0, SM2 should be 0. Enables serial reception. Set by software to enable reception. Clear by software to disable reception. The 9th data bit that will be transmitted in Modes 2 and 3. Set or clear by software as desired. In Modes 2 and 3, is the 9th data bit that was received. In Mode 1, it SM2=0, RB8 is the stop bit that was received. In Mode 0, RB8 is not used. Transmit interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or at the beginning of the stop bit in the other modes, in any serial transmission. Must be cleared by software. Receive interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or halfway through the stop bit time in the other modes, in any serial reception (except see SM2). Must be cleared by software.
SU01626
REN TB8 RB8 TI RI
Figure 13. Serial Port Control (SCON) Register Baud Rate Mode Mode 0 Max Mode 2 Max Mode 1, 3 Max Mode 1, 3 12-clock mode 1.67 MHz 625 k 104.2 k 19.2 k 9.6 k 4.8 k 2.4 k 1.2 k 137.5 110 110 6-clock mode 3.34 MHz 1250 k 208.4 k 38.4 k 19.2 k 9.6 k 4.8 k 2.4 k 275 220 220 fosc 20 MHz 20 MHz 20 MHz 11.059 MHz 11.059 MHz 11.059 MHz 11.059 MHz 11.059 MHz 11.986 MHz 6 MHz 12 MHz SMOD C/T X 1 1 1 0 0 0 0 0 0 0 X X 0 0 0 0 0 0 0 0 0 Mode X X 2 2 2 2 2 2 2 2 1 Reload Value X X FFH FDH FDH FAH F4H E8H 1DH 72H FEEBH Timer 1
Figure 14. Timer 1 Generated Commonly Used Baud Rates More About Mode 0 Serial data enters and exits through RxD. TxD outputs the shift clock. 8 bits are transmitted/received: 8 data bits (LSB first). The baud rate is fixed a 1/12 the oscillator frequency (12-clock mode) or 1/6 the oscillator frequency (6-clock mode). Figure 15 shows a simplified functional diagram of the serial port in Mode 0, and associated timing. Transmission is initiated by any instruction that uses SBUF as a destination register. The "write to SBUF" signal at S6P2 also loads a 1 into the 9th position of the transmit shift register and tells the TX Control block to commence a transmission. The internal timing is such that one full machine cycle will elapse between "write to SBUF" and activation of SEND. SEND enables the output of the shift register to the alternate output function line of P3.0 and also enable SHIFT CLOCK to the alternate output function line of P3.1. SHIFT CLOCK is LOW during S3, S4, and S5 of every machine cycle, and HIGH during S6, S1, and S2. At 2004 Apr 20 22 S6P2 of every machine cycle in which SEND is active, the contents of the transmit shift are shifted to the right one position. As data bits shift out to the right, zeros come in from the left. When the MSB of the data byte is at the output position of the shift register, then the 1 that was initially loaded into the 9th position, is just to the left of the MSB, and all positions to the left of that contain zeros. This condition flags the TX Control block to do one last shift and then deactivate SEND and set T1. Both of these actions occur at S1P1 of the 10th machine cycle after "write to SBUF." Reception is initiated by the condition REN = 1 and R1 = 0. At S6P2 of the next machine cycle, the RX Control unit writes the bits 11111110 to the receive shift register, and in the next clock phase activates RECEIVE. RECEIVE enable SHIFT CLOCK to the alternate output function line of P3.1. SHIFT CLOCK makes transitions at S3P1 and S6P1 of every machine cycle. At S6P2 of every machine cycle in which RECEIVE is active, the contents of the receive shift register are
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
shifted to the left one position. The value that comes in from the right is the value that was sampled at the P3.0 pin at S5P2 of the same machine cycle. As data bits come in from the right, 1s shift out to the left. When the 0 that was initially loaded into the rightmost position arrives at the leftmost position in the shift register, it flags the RX Control block to do one last shift and load SBUF. At S1P1 of the 10th machine cycle after the write to SCON that cleared RI, RECEIVE is cleared as RI is set. More About Mode 1 Ten bits are transmitted (through TxD), or received (through RxD): a start bit (0), 8 data bits (LSB first), and a stop bit (1). On receive, the stop bit goes into RB8 in SCON. In the 80C51 the baud rate is determined by the Timer 1 or Timer 2 overflow rate. Figure 16 shows a simplified functional diagram of the serial port in Mode 1, and associated timings for transmit receive. Transmission is initiated by any instruction that uses SBUF as a destination register. The "write to SBUF" signal also loads a 1 into the 9th bit position of the transmit shift register and flags the TX Control unit that a transmission is requested. Transmission actually commences at S1P1 of the machine cycle following the next rollover in the divide-by-16 counter. (Thus, the bit times are synchronized to the divide-by-16 counter, not to the "write to SBUF" signal.) The transmission begins with activation of SEND which puts the start bit at TxD. One bit time later, DATA is activated, which enables the output bit of the transmit shift register to TxD. The first shift pulse occurs one bit time after that. As data bits shift out to the right, zeros are clocked in from the left. When the MSB of the data byte is at the output position of the shift register, then the 1 that was initially loaded into the 9th position is just to the left of the MSB, and all positions to the left of that contain zeros. This condition flags the TX Control unit to do one last shift and then deactivate SEND and set TI. This occurs at the 10th divide-by-16 rollover after "write to SBUF." Reception is initiated by a detected 1-to-0 transition at RxD. For this purpose RxD is sampled at a rate of 16 times whatever baud rate has been established. When a transition is detected, the divide-by-16 counter is immediately reset, and 1FFH is written into the input shift register. Resetting the divide-by-16 counter aligns its rollovers with the boundaries of the incoming bit times. The 16 states of the counter divide each bit time into 16ths. At the 7th, 8th, and 9th counter states of each bit time, the bit detector samples the value of RxD. The value accepted is the value that was seen in at least 2 of the 3 samples. This is done for noise rejection. If the value accepted during the first bit time is not 0, the receive circuits are reset and the unit goes back to looking for another 1-to-0 transition. This is to provide rejection of false start bits. If the start bit proves valid, it is shifted into the input shift register, and reception of the rest of the frame will proceed. As data bits come in from the right, 1s shift out to the left. When the start bit arrives at the leftmost position in the shift register (which in mode 1 is a 9-bit register), it flags the RX Control block to do one last shift, load SBUF and RB8, and set RI. The signal to load SBUF and RB8, and to set RI, will be generated if, and only if, the following conditions are met at the time the final shift pulse is generated.: 1. RI = 0, and 2. Either SM2 = 0, or the received stop bit = 1. If either of these two conditions is not met, the received frame is irretrievably lost. If both conditions are met, the stop bit goes into RB8, the 8 data bits go into SBUF, and RI is activated. At this time,
whether the above conditions are met or not, the unit goes back to looking for a 1-to-0 transition in RxD. More About Modes 2 and 3 Eleven bits are transmitted (through TxD), or received (through RxD): a start bit (0), 8 data bits (LSB first), a programmable 9th data bit, and a stop bit (1). On transmit, the 9th data bit (TB8) can be assigned the value of 0 or 1. On receive, the 9the data bit goes into RB8 in SCON. The baud rate is programmable to either 1/32 or 1/64 (12-clock mode) or 1/16 or 1/32 the oscillator frequency (6-clock mode) the oscillator frequency in Mode 2. Mode 3 may have a variable baud rate generated from Timer 1 or Timer 2. Figures 17 and 18 show a functional diagram of the serial port in Modes 2 and 3. The receive portion is exactly the same as in Mode 1. The transmit portion differs from Mode 1 only in the 9th bit of the transmit shift register. Transmission is initiated by any instruction that uses SBUF as a destination register. The "write to SBUF" signal also loads TB8 into the 9th bit position of the transmit shift register and flags the TX Control unit that a transmission is requested. Transmission commences at S1P1 of the machine cycle following the next rollover in the divide-by-16 counter. (Thus, the bit times are synchronized to the divide-by-16 counter, not to the "write to SBUF" signal.) The transmission begins with activation of SEND, which puts the start bit at TxD. One bit time later, DATA is activated, which enables the output bit of the transmit shift register to TxD. The first shift pulse occurs one bit time after that. The first shift clocks a 1 (the stop bit) into the 9th bit position of the shift register. Thereafter, only zeros are clocked in. Thus, as data bits shift out to the right, zeros are clocked in from the left. When TB8 is at the output position of the shift register, then the stop bit is just to the left of TB8, and all positions to the left of that contain zeros. This condition flags the TX Control unit to do one last shift and then deactivate SEND and set TI. This occurs at the 11th divide-by-16 rollover after "write to SUBF." Reception is initiated by a detected 1-to-0 transition at RxD. For this purpose RxD is sampled at a rate of 16 times whatever baud rate has been established. When a transition is detected, the divide-by-16 counter is immediately reset, and 1FFH is written to the input shift register. At the 7th, 8th, and 9th counter states of each bit time, the bit detector samples the value of R-D. The value accepted is the value that was seen in at least 2 of the 3 samples. If the value accepted during the first bit time is not 0, the receive circuits are reset and the unit goes back to looking for another 1-to-0 transition. If the start bit proves valid, it is shifted into the input shift register, and reception of the rest of the frame will proceed. As data bits come in from the right, 1s shift out to the left. When the start bit arrives at the leftmost position in the shift register (which in Modes 2 and 3 is a 9-bit register), it flags the RX Control block to do one last shift, load SBUF and RB8, and set RI. The signal to load SBUF and RB8, and to set RI, will be generated if, and only if, the following conditions are met at the time the final shift pulse is generated. 1. RI = 0, and 2. Either SM2 = 0, or the received 9th data bit = 1. If either of these conditions is not met, the received frame is irretrievably lost, and RI is not set. If both conditions are met, the received 9th data bit goes into RB8, and the first 8 data bits go into SBUF. One bit time later, whether the above conditions were met or not, the unit goes back to looking for a 1-to-0 transition at the RxD input.
2004 Apr 20
23
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
80C51 Internal Bus
Write to SBUF D
S CL
Q
SBUF
RxD P3.0 Alt Output Function
Zero Detector
Start TX Control S6 Serial Port Interrupt RX Clock R1 RX Control REN RI Start LSB Input Shift Register 1 1 1 1 1 1 1 TX Clock T1
Shift
Send
Receive Shift 0 MSB
Shift Clock
TxD P3.1 Alt Output Function
Shift Load SBUF
RxD P3.0 Alt Input Function
LSB
SBUF
MSB
Read SBUF
80C51 Internal Bus
S4 . . ALE
S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1
Write to SBUF Send Shift S6P2 Transmit D0 D1 D2 D3 D4 D5 D6 D7
RxD (Data Out) TxD (Shift Clock) TI
S3P1
S6P1
Write to SCON (Clear RI) RI Receive Shift RxD (Data In) D0 S5P2 TxD (Shift Clock) D1 D2 D3 D4 D5 D6 D7 Receive
SU00539
Figure 15. Serial Port Mode 0
2004 Apr 20
24
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Timer 1 Overflow TB8
80C51 Internal Bus
/2 SMOD = 0 SMOD = 1
Write to SBUF D CL
S
Q
SBUF TxD
Zero Detector
Start TX Control / 16 Serial Port Interrupt / 16 TX Clock T1
Shift
Data
Send
Sample 1-to-0 Transition Detector Start
RX Clock RI RX Control
Load SBUF Shift 1FFH
Bit Detector Input Shift Register (9 Bits) Shift RxD Load SBUF
SBUF
Read SBUF
80C51 Internal Bus TX Clock Write to SBUF Send Data Shift TxD TI / 16 Reset RX Clock RxD Bit Detector Sample Times Shift RI Start Bit D0 D1 D2 D3 D4 D5 D6 D7 Stop Bit Receive Start Bit D0 D1 D2 D3 D4 D5 D6 D7 Stop Bit S1P1 Transmit
SU00540
Figure 16. Serial Port Mode 1
2004 Apr 20
25
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
80C51 Internal Bus TB8
Write to SBUF D CL Phase 2 Clock (1/2 fOSC)
S
Q
SBUF
TxD
Zero Detector
Mode 2 Start / 16 Serial Port Interrupt SMOD = 0 (SMOD is PCON.7) Sample 1-to-0 Transition Detector Start / 16
Stop Bit Gen. TX Control T1
Shift
Data
SMOD = 1 /2
TX Clock
Send
RX Clock
R1
Load SBUF Shift 1FFH
RX Control
Bit Detector Input Shift Register (9 Bits) Shift RxD Load SBUF
SBUF
Read SBUF
80C51 Internal Bus TX Clock Write to SBUF Send Data Shift TxD TI Stop Bit Gen. / 16 Reset RX Clock RxD Bit Detector Sample Times Shift RI Start Bit D0 D1 D2 D3 D4 D5 D6 D7 RB8 Stop Bit Receive Start Bit D0 D1 D2 D3 D4 D5 D6 D7 TB8 Stop Bit S1P1 Transmit
SU00541
Figure 17. Serial Port Mode 2 2004 Apr 20 26
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Timer 1 Overflow TB8
80C51 Internal Bus
/2
SMOD = 0 SMOD = 1
Write to SBUF D CL
S
Q
SBUF TxD
Zero Detector
Start TX Control
Shift
Data
/ 16
Serial Port Interrupt
TX Clock
T1
Send
/ 16
R1 Load SBUF Shift 1FFH
Sample 1-to-0 Transition Detector Start
RX Clock
RX Control
Bit Detector Input Shift Register (9 Bits) Shift RxD Load SBUF
SBUF
Read SBUF
80C51 Internal Bus TX Clock Write to SBUF Send Data Shift TxD TI Stop Bit Gen. RX Clock RxD Bit Detector Sample Times Shift RI / 16 Reset Start Bit D0 D1 D2 D3 D4 D5 D6 D7 TB8 Stop Bit S1P1 Transmit
Start Bit
D0
D1
D2
D3
D4
D5
D6
D7
RB8
Stop Bit Receive
SU00542
Figure 18. Serial Port Mode 3 2004 Apr 20 27
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Enhanced Features
The UART operates in all of the usual modes that are described in the first section of Data Handbook IC20, 80C51-Based 8-Bit Microcontrollers. In addition the UART can perform framing error detect by looking for missing stop bits, and automatic address recognition. The UART also fully supports multiprocessor communication as does the standard 80C51 UART. When used for framing error detect the UART looks for missing stop bits in the communication. A missing bit will set the FE bit in the SCON register. The FE bit shares the SCON.7 bit with SM0 and the function of SCON.7 is determined by PCON.6 (SMOD0) (see Figure 13). If SMOD0 is set then SCON.7 functions as FE. SCON.7 functions as SM0 when SMOD0 is cleared. When used as FE SCON.7 can only be cleared by software. Refer to Figure 19. Automatic Address Recognition Automatic Address Recognition is a feature which allows the UART to recognize certain addresses in the serial bit stream by using hardware to make the comparisons. This feature saves a great deal of software overhead by eliminating the need for the software to examine every serial address which passes by the serial port. This feature is enabled by setting the SM2 bit in SCON. In the 9 bit UART modes, mode 2 and mode 3, the Receive Interrupt flag (RI) will be automatically set when the received byte contains either the "Given" address or the "Broadcast" address. The 9-bit mode requires that the 9th information bit is a 1 to indicate that the received information is an address and not data. Automatic address recognition is shown in Figure 20. The 8 bit mode is called Mode 1. In this mode the RI flag will be set if SM2 is enabled and the information received has a valid stop bit following the 8 address bits and the information is either a Given or Broadcast address. Mode 0 is the Shift Register mode and SM2 is ignored. Using the Automatic Address Recognition feature allows a master to selectively communicate with one or more slaves by invoking the Given slave address or addresses. All of the slaves may be contacted by using the Broadcast address. Two special Function Registers are used to define the slave's address, SADDR, and the address mask, SADEN. SADEN is used to define which bits in the SADDR are to b used and which bits are "don't care". The SADEN mask can be logically ANDed with the SADDR to create the "Given" address which the master will use for addressing each of the slaves. Use of the Given address allows multiple slaves to be recognized while excluding others. The following examples will help to show the versatility of this scheme: Slave 0 SADDR = SADEN = Given = 1100 0000 1111 1101 1100 00X0
Slave 1
SADDR = SADEN = Given =
1100 0000 1111 1110 1100 000X
In the above example SADDR is the same and the SADEN data is used to differentiate between the two slaves. Slave 0 requires a 0 in bit 0 and it ignores bit 1. Slave 1 requires a 0 in bit 1 and bit 0 is ignored. A unique address for Slave 0 would be 1100 0010 since slave 1 requires a 0 in bit 1. A unique address for slave 1 would be 1100 0001 since a 1 in bit 0 will exclude slave 0. Both slaves can be selected at the same time by an address which has bit 0 = 0 (for slave 0) and bit 1 = 0 (for slave 1). Thus, both could be addressed with 1100 0000. In a more complex system the following could be used to select slaves 1 and 2 while excluding slave 0: Slave 0 SADDR = SADEN = Given = SADDR = SADEN = Given = SADDR = SADEN = Given = 1100 0000 1111 1001 1100 0XX0 1110 0000 1111 1010 1110 0X0X 1110 0000 1111 1100 1110 00XX
Slave 1
Slave 2
In the above example the differentiation among the 3 slaves is in the lower 3 address bits. Slave 0 requires that bit 0 = 0 and it can be uniquely addressed by 1110 0110. Slave 1 requires that bit 1 = 0 and it can be uniquely addressed by 1110 and 0101. Slave 2 requires that bit 2 = 0 and its unique address is 1110 0011. To select Slaves 0 and 1 and exclude Slave 2 use address 1110 0100, since it is necessary to make bit 2 = 1 to exclude slave 2. The Broadcast Address for each slave is created by taking the logical OR of SADDR and SADEN. Zeros in this result are trended as don't-cares. In most cases, interpreting the don't-cares as ones, the broadcast address will be FF hexadecimal. Upon reset SADDR (SFR address 0A9H) and SADEN (SFR address 0B9H) are leaded with 0s. This produces a given address of all "don't cares" as well as a Broadcast address of all "don't cares". This effectively disables the Automatic Addressing mode and allows the microcontroller to use standard 80C51 type UART drivers which do not make use of this feature.
2004 Apr 20
28
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
D0
D1
D2
D3
D4
D5
D6
D7
D8
START BIT
DATA BYTE
ONLY IN MODE 2, 3
STOP BIT
SET FE BIT IF STOP BIT IS 0 (FRAMING ERROR) SM0 TO UART MODE CONTROL
SM0 / FE
SM1
SM2
REN
TB8
RB8
TI
RI
SCON (98H)
SMOD1
SMOD0
-
POF
LVF
GF0
GF1
IDL
PCON (87H)
0 : SCON.7 = SM0 1 : SCON.7 = FE
SU00044
Figure 19. UART Framing Error Detection
D0
D1
D2
D3
D4
D5
D6
D7
D8
SM0 1 1
SM1 1 0
SM2 1
REN 1
TB8 X
RB8
TI
RI
SCON (98H)
RECEIVED ADDRESS D0 TO D7 PROGRAMMED ADDRESS COMPARATOR
IN UART MODE 2 OR MODE 3 AND SM2 = 1: INTERRUPT IF REN=1, RB8=1 AND "RECEIVED ADDRESS" = "PROGRAMMED ADDRESS" - WHEN OWN ADDRESS RECEIVED, CLEAR SM2 TO RECEIVE DATA BYTES - WHEN ALL DATA BYTES HAVE BEEN RECEIVED: SET SM2 TO WAIT FOR NEXT ADDRESS.
SU00045
Figure 20. UART Multiprocessor Communication, Automatic Address Recognition
2004 Apr 20
29
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
I2C-bus Serial I/O The I2C-bus serial port is identical to the I2C-bus serial port on the 8xC554 and 8xC652 devices. Note that in the P8xC654X2, the I2C-bus pins are alternate functions to port pins P1.6 and P1.7. Because of this, P1.6 and P1.7 on these parts do not have a pull-up structure as found on the 80C51; P1.6 and P1.7 have open drain outputs. The I2C-bus uses two wires (SDA and SCL) to transfer information between devices connected to the bus. The main features of the bus are: - Bidirectional data transfer between masters and slaves - Multimaster bus (no central master) - Arbitration between simultaneously transmitting masters without corruption of serial data on the bus - Serial clock synchronization allows devices with different bit rates to communicate via one serial bus - Serial clock synchronization can be used as a handshake mechanism to suspend and resume serial transfer - The I2C-bus may be used for test and diagnostic purposes The output latches of P1.6 and P1.7 must be set to logic 1 in order to enable I2C-bus. The P8xC654X2 on-chip I2C-bus logic provides a serial interface that meets the I2C-bus specification and supports all transfer modes (other than the low-speed mode) from and to the I2C-bus. The I2C-bus logic handles bytes transfer autonomously. It also keeps track of serial transfers, and a status register (S1STA) reflects the status of the I2C-bus. The CPU interfaces to the I2C-bus logic via the following four special function registers: S1CON (I2C-bus control register), S1STA (I2C-bus status register), S1DAT (I2C-bus data register), and S1ADR (I2C-bus slave address register). The I2C-bus logic interfaces to the external I2C-bus via two port 1 pins: P1.6/SCL (serial clock line) and P1.7/SDA (serial data line). A typical I2C-bus configuration is shown in Figure 21, and Figure 22 shows how a data transfer is accomplished on the bus. Depending on the state of the direction bit (R/W), two types of data transfers are possible on the I2C-bus: 1. Data transfer from a master transmitter to a slave receiver. The first byte transmitted by the master is the slave address. Next follows a number of data bytes. The slave returns an acknowledge bit after each received byte. 2. Data transfer from a slave transmitter to a master receiver. The first byte (the slave address) is transmitted by the master. The slave then returns an acknowledge bit. Next follows the data bytes transmitted by the slave to the master. The master returns an acknowledge bit after all received bytes other than the last byte. At the end of the last received byte, a "not acknowledge" is returned. The master device generates all of the serial clock pulses and the START and STOP conditions. A transfer is ended with a STOP
condition or with a repeated START condition. Since a repeated START condition is also the beginning of the next serial transfer, the I2C-bus will not be released. Modes of Operation: The on-chip I2C-bus logic may operate in the following four modes: 1. Master Transmitter Mode: Serial data output through P1.7/SDA while P1.6/SCL outputs the serial clock. The first byte transmitted contains the slave address of the receiving device (7 bits) and the data direction bit. In this case the data direction bit (R/W) will be logic 0, and we say that a "W" is transmitted. Thus the first byte transmitted is SLA+W. Serial data is transmitted 8 bits at a time. After each byte is transmitted, an acknowledge bit is received. START and STOP conditions are output to indicate the beginning and the end of a serial transfer. 2. Master Receiver Mode: The first byte transmitted contains the slave address of the transmitting device (7 bits) and the data direction bit. In this case the data direction bit (R/W) will be logic 1, and we say that an "R" is transmitted. Thus the first byte transmitted is SLA+R. Serial data is received via P1.7/SDA while P1.6/SCL outputs the serial clock. Serial data is received 8 bits at a time. After each byte is received, an acknowledge bit is transmitted. START and STOP conditions are output to indicate the beginning and end of a serial transfer. 3. Slave Receiver Mode: Serial data and the serial clock are received through P1.7/SDA and P1.6/SCL. After each byte is received, an acknowledge bit is transmitted. START and STOP conditions are recognized as the beginning and end of a serial transfer. Address recognition is performed by hardware after reception of the slave address and direction bit. 4. Slave Transmitter Mode: The first byte is received and handled as in the slave receiver mode. However, in this mode, the direction bit will indicate that the transfer direction is reversed. Serial data is transmitted via P1.7/SDA while the serial clock is input through P1.6/SCL. START and STOP conditions are recognized as the beginning and end of a serial transfer. In a given application, I2C-bus may operate as a master and as a slave. In the slave mode, the I2C-bus hardware looks for its own slave address and the general call address. If one of these addresses is detected, an interrupt is requested. When the microcontroller wishes to become the bus master, the hardware waits until the bus is free before the master mode is entered so that a possible slave action is not interrupted. If bus arbitration is lost in the master mode, the I2C-bus switches to the slave mode immediately and can detect its own slave address in the same serial transfer.
2004 Apr 20
30
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
VDD RP RP SDA I2C-bus SCL
P1.7/SDA
P1.6/SCL OTHER DEVICE WITH I2C-BUS INTERFACE OTHER DEVICE WITH I2C-BUS INTERFACE
P8xC654X2
SU01734
Figure 21. Typical I2C-bus configuration
SDA
STOP CONDITION REPEATED START CONDITION SLAVE ADDRESS R/W DIRECTION BIT ACKNOWLEDGMENT SIGNAL FROM RECEIVER
MSB
ACKNOWLEDGMENT SIGNAL FROM RECEIVER
CLOCK LINE HELD LOW WHILE INTERRUPTS ARE SERVICED
SCL S START CONDITION
1
2
7
8
9 ACK
1
2
3-8
9 ACK
P/S
REPEATED IF MORE BYTES ARE TRANSFERRED
SU00965
Figure 22. Data Transfer on the I2C-bus Implementation and Operation: Figure 23 shows how the on-chip I2C-bus interface is implemented, and the following text describes the individual blocks. INPUT FILTERS AND OUTPUT STAGES The input filters have I2C-bus compatible input levels. If the input voltage is less than 1.5 V, the input logic level is interpreted as 0; if the input voltage is greater than 3.0 V, the input logic level is interpreted as 1. Input signals are synchronized with the internal clock (fOSC/4), and spikes shorter than three oscillator periods are filtered out. The output stages consist of open drain transistors that can sink 3mA at VOUT < 0.4 V. These open drain outputs do not have clamping diodes to VDD. Thus, if the device is connected to the I2C-bus and VDD is switched off, the I2C-bus is not affected. ADDRESS REGISTER, S1ADR This 8-bit special function register may be loaded with the 7-bit slave address (7 most significant bits) to which the I2C-bus will respond
I2C-bus
when programmed as a slave transmitter or receiver. The LSB (GC) is used to enable general call address (00H) recognition. COMPARATOR The comparator compares the received 7-bit slave address with its own slave address (7 most significant bits in S1ADR). It also compares the first received 8-bit byte with the general call address (00H). If an equality is found, the appropriate status bits are set and an interrupt is requested. SHIFT REGISTER, S1DAT This 8-bit special function register contains a byte of serial data to be transmitted or a byte which has just been received. Data in S1DAT is always shifted from right to left; the first bit to be transmitted is the MSB (bit 7) and, after a byte has been received, the first bit of received data is located at the MSB of S1DAT. While data is being shifted out, data on the bus is simultaneously being shifted in; S1DAT always contains the last byte present on the bus. Thus, in the event of lost arbitration, the transition from master transmitter to slave receiver is made with the correct data in S1DAT.
2004 Apr 20
31
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
8
S1ADR
ADDRESS REGISTER
P1.7
COMPARATOR INPUT FILTER
P1.7/SDA OUTPUT STAGE S1DAT SHIFT REGISTER ACK
8
INPUT FILTER
ARBITRATION & SYNC LOGIC
P1.6/SCL OUTPUT STAGE TIMER 1 OVERFLOW S1CON P1.6 SERIAL CLOCK GENERATOR
TIMING & CONTROL LOGIC
fOSC/4
INTERRUPT
CONTROL REGISTER
8
STATUS BITS
STATUS DECODER
S1STA
STATUS REGISTER 8
su00966
Figure 23.
I2C-bus
Serial Interface Block Diagram
2004 Apr 20
32
INTERNAL BUS
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
ARBITRATION AND SYNCHRONIZATION LOGIC In the master transmitter mode, the arbitration logic checks that every transmitted logic 1 actually appears as a logic 1 on the I2C-bus. If another device on the bus overrules a logic 1 and pulls the SDA line LOW, arbitration is lost, and the I2C-bus immediately changes from master transmitter to slave receiver. The I2C-bus will continue to output clock pulses (on SCL) until transmission of the current serial byte is complete. Arbitration may also be lost in the master receiver mode. Loss of arbitration in this mode can only occur while the I2C-bus is returning a "not acknowledge: (logic 1) to the bus. Arbitration is lost when another device on the bus pulls this signal LOW. Since this can occur only at the end of a serial byte, the I2C-bus generates no further clock pulses. Figure 24 shows the arbitration procedure.
The synchronization logic will synchronize the serial clock generator with the clock pulses on the SCL line from another device. If two or more master devices generate clock pulses, the "mark" duration is determined by the device that generates the shortest "marks," and the "space" duration is determined by the device that generates the longest "spaces." Figure 25 shows the synchronization procedure. A slave may stretch the space duration to slow down the bus master. The space duration may also be stretched for handshaking purposes. This can be done after each bit or after a complete byte transfer. The I2C-bus will stretch the SCL space duration after a byte has been transmitted or received and the acknowledge bit has been transferred. The serial interrupt flag (SI) is set, and the stretching continues until the serial interrupt flag is cleared.
(3) (1) (1) (2)
SDA
SCL
1
2
3
4
8
9 ACK
1. Another device transmits identical serial data. 2. Another device overrules a logic 1 (dotted line) transmitted by SIO1 (master) by pulling the SDA line low. Arbitration is lost, and SIO1 enters the slave receiver mode. 3. SIO1 is in the slave receiver mode but still generates clock pulses until the current byte has been transmitted. SIO1 will not generate clock pulses for the next byte. Data on SDA originates from the new master once it has won arbitration.
SU00967
Figure 24. Arbitration Procedure
SDA
(1)
(3)
(1)
SCL
(2)
MARK DURATION
SPACE DURATION
1. Another service pulls the SCL line low before the SIO1 "mark" duration is complete. The serial clock generator is immediately reset and commences with the "space" duration by pulling SCL low. 2. Another device still pulls the SCL line low after SIO1 releases SCL. The serial clock generator is forced into the wait state until the SCL line is released. 3. The SCL line is released, and the serial clock generator commences with the mark duration.
SU00968
Figure 25. Serial Clock Synchronization
2004 Apr 20
33
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
SERIAL CLOCK GENERATOR This programmable clock pulse generator provides the SCL clock pulses when the I2C-bus is in the master transmitter or master receiver mode. It is switched off when the I2C-bus is in a slave mode. In standard speed mode, the programmable output clock frequencies are: fOSC/120, fOSC/9600, and the Timer 1 overflow rate divided by eight. The output clock pulses have a 50 % duty cycle unless the clock generator is synchronized with other SCL clock sources as described above. TIMING AND CONTROL The timing and control logic generates the timing and control signals for serial byte handling. This logic block provides the shift pulses for S1DAT, enables the comparator, generates and detects start and stop conditions, receives and transmits acknowledge bits, controls the master and slave modes, contains interrupt request logic, and monitors the I2C-bus status. CONTROL REGISTER, S1CON This 7-bit special function register is used by the microcontroller to control the following I2C-bus functions: start and restart of a serial transfer, termination of a serial transfer, bit rate, address recognition, and acknowledgment. STATUS DECODER AND STATUS REGISTER The status decoder takes all of the internal status bits and compresses them into a 5-bit code. This code is unique for each I2C-bus status. The 5-bit code may be used to generate vector addresses for fast processing of the various service routines. Each service routine processes a particular bus status. There are 26 possible bus states if all four modes of the I2C-bus are used. The 5-bit status code is latched into the five most significant bits of the status register when the serial interrupt flag is set (by hardware) and remains stable until the interrupt flag is cleared by software. The three least significant bits of the status register are always zero. If the status code is used as a vector to service routines, then the routines are displaced by eight address locations. Eight bytes of code is sufficient for most of the service routines (see the software example in this section). The Four I2C-bus Special Function Registers: The microcontroller interfaces to the I2C-bus via four special function registers. These four SFRs (S1ADR, S1DAT, S1CON, and S1STA) are described individually in the following sections. The Address Register, S1ADR: The CPU can read from and write to this 8-bit, directly addressable SFR. S1ADR is not affected by the the I2C-bus hardware. The contents of this register are irrelevant when the I2C-bus is in a master mode. In the slave modes, the seven most significant bits must be loaded with the microcontroller's own slave address, and, if the least significant bit is set, the general call address (00H) is recognized; otherwise it is ignored. 7 S1ADR (DBH) X 6 X 5 X 4 X 3 X 2 X 1 X 0 GC
not in the process of shifting a byte. This occurs when the I2C-bus is in a defined state and the serial interrupt flag is set. Data in S1DAT remains stable as long as SI is set. Data in S1DAT is always shifted from right to left: the first bit to be transmitted is the MSB (bit 7), and, after a byte has been received, the first bit of received data is located at the MSB of S1DAT. While data is being shifted out, data on the bus is simultaneously being shifted in; S1DAT always contains the last data byte present on the bus. Thus, in the event of lost arbitration, the transition from master transmitter to slave receiver is made with the correct data in S1DAT. 7 S1DAT (DAH) SD7 - SD0: Eight bits to be transmitted or just received. A logic 1 in S1DAT corresponds to a HIGH level on the I2C-bus, and a logic 0 corresponds to a LOW level on the bus. Serial data shifts through S1DAT from right to left. Figure 26 shows how data in S1DAT is serially transferred to and from the SDA line. S1DAT and the ACK flag form a 9-bit shift register which shifts in or shifts out an 8-bit byte, followed by an acknowledge bit. The ACK flag is controlled by the I2C-bus hardware and cannot be accessed by the CPU. Serial data is shifted through the ACK flag into S1DAT on the rising edges of serial clock pulses on the SCL line. When a byte has been shifted into S1DAT, the serial data is available in S1DAT, and the acknowledge bit is returned by the control logic during the ninth clock pulse. Serial data is shifted out from S1DAT via a buffer (BSD7) on the falling edges of clock pulses on the SCL line. When the CPU writes to S1DAT, BSD7 is loaded with the content of S1DAT.7, which is the first bit to be transmitted to the SDA line (see Figure 27). After nine serial clock pulses, the eight bits in S1DAT will have been transmitted to the SDA line, and the acknowledge bit will be present in ACK. Note that the eight transmitted bits are shifted back into S1DAT. The Control Register, S1CON: The CPU can read from and write to this 8-bit, directly addressable SFR. Two bits are affected by the I2C hardware: the SI bit is set when a serial interrupt is requested, and the STO bit is cleared when a STOP condition is present on the I2C-bus. The STO bit is also cleared when ENS1 = 0. 7 S1CON (D8H) CR2 6 ENS1 5 STA 4 STO 3 SI 2 AA 1 CR1 0 CR0 6 5 SD5 4 SD4 3 2 1 0
SD7 SD6
SD3 SD2
SD1 SD0
shift direction
own slave address
ENS1, THE I2C ENABLE BIT ENS1 = 0: When ENS1 is logic 0, the SDA and SCL outputs are in a high impedance state. SDA and SCL input signals are ignored, I2C is in the "not addressed" slave state, and the STO bit in S1CON is forced to 0. No other bits are affected. P1.6 and P1.7 may be used as open drain I/O ports. ENS1 = 1: When ENS1 is "1", I2C is enabled. The P1.6 and P1.7 port latches must be set to logic 1. ENS1 should not be used to temporarily release I2C from the I2C-bus since, when ENS1 is reset, the I2C-bus status is lost. The AA flag should be used instead (see description of the AA flag in the following text).
The most significant bit corresponds to the first bit received from the I2C-bus after a start condition. A logic 1 in S1ADR corresponds to a HIGH level on the I2C-bus, and a logic 0 corresponds to a LOW level on the bus. The Data Register, S1DAT: S1DAT contains a byte of serial data to be transmitted or a byte which has just been received. The CPU can read from and write to this 8-bit, directly addressable SFR while it is
2004 Apr 20
34
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
INTERNAL BUS
SDA
8
BSD7
S1DAT
ACK
SCL SHIFT PULSES
SU00969
Figure 26. Serial Input/Output Configuration
SDA
D7
D6
D5
D4
D3
D2
D1
D0
A
SCL
SHIFT ACK & S1DAT SHIFT IN
ACK
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
A
S1DAT
(1)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(1)
SHIFT BSD7 SHIFT OUT
BSD7
D7
D6
D5
D4
D3
D2
D1
D0
(3)
LOADED BY THE CPU (1) Valid data in S1DAT (2) Shifting data in S1DAT and ACK (3) High level on SDA
SU00970
Figure 27. Shift-in and Shift-out Timing In the following text, it is assumed that ENS1 = 1. STA, THE START FLAG STA = 1: When the STA bit is set to enter a master mode, the I2C hardware checks the status of the I2C-bus and generates a START condition if the bus is free. If the bus is not free, then I2C waits for a STOP condition (which will free the bus) and generates a START condition after a delay of a half clock period of the internal serial clock generator. If STA is set while I2C is already in a master mode and one or more bytes are transmitted or received, I2C transmits a repeated START condition. STA may be set at any time. STA may also be set when I2C is an addressed slave. STA = 0: When the STA bit is reset, no START condition or repeated START condition will be generated. STO, THE STOP FLAG STO = 1: When the STO bit is set while I2C is in a master mode, a STOP condition is transmitted to the I2C-bus. When the STOP condition is detected on the bus, the I2C hardware clears the STO flag. In a slave mode, the STO flag may be set to recover from an error condition. In this case, no STOP condition is transmitted to the I2C-bus. However, the I2C hardware behaves as if a STOP condition has been received and switches to the defined "not addressed" slave receiver mode. The STO flag is automatically cleared by hardware.
2004 Apr 20
35
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
If the STA and STO bits are both set, the a STOP condition is transmitted to the I2C-bus if I2C is in a master mode (in a slave mode, I2C generates an internal STOP condition which is not transmitted). I2C then transmits a START condition. STO = 0: When the STO bit is reset, no STOP condition will be generated. SI, THE SERIAL INTERRUPT FLAG SI = 1: When the SI flag is set, then, if the EA and ES1 (interrupt enable register) bits are also set, a serial interrupt is requested. SI is set by hardware when one of 25 of the 26 possible I2C states is entered. The only state that does not cause SI to be set is state F8H, which indicates that no relevant state information is available. While SI is set, the LOW period of the serial clock on the SCL line is stretched, and the serial transfer is suspended. A HIGH level on the SCL line is unaffected by the serial interrupt flag. SI must be reset by software. SI = 0: When the SI flag is reset, no serial interrupt is requested, and there is no stretching of the serial clock on the SCL line. AA, THE ASSERT ACKNOWLEDGE FLAG AA = 1: If the AA flag is set, an acknowledge (low level to SDA) will be returned during the acknowledge clock pulse on the SCL line when: - The "own slave address" has been received - The general call address has been received while the general call bit (GC) in S1ADR is set - A data byte has been received while I2C is in the master receiver mode - A data byte has been received while I2C is in the addressed slave receiver mode AA = 0: if the AA flag is reset, a not acknowledge (HIGH level to SDA) will be returned during the acknowledge clock pulse on SCL when: - A data has been received while I2C is in the master receiver mode - A data byte has been received while I2C is in the addressed slave receiver mode When I2C is in the addressed slave transmitter mode, state C8H will be entered after the last serial is transmitted (see Figure 31). When SI is cleared, I2C leaves state C8H, enters the not addressed slave receiver mode, and the SDA line remains at a HIGH level. In state C8H, the AA flag can be set again for future address recognition.
When I2C is in the not addressed slave mode, its own slave address and the general call address are ignored. Consequently, no acknowledge is returned, and a serial interrupt is not requested. Thus, I2C can be temporarily released from the I2C-bus while the bus status is monitored. While I2C is released from the bus, START and STOP conditions are detected, and serial data is shifted in. Address recognition can be resumed at any time by setting the AA flag. If the AA flag is set when the part's own slave address or the general call address has been partly received, the address will be recognized at the end of the byte transmission. CR0, CR1, AND CR2, THE CLOCK RATE BITS These three bits determine the serial clock frequency when I2C is in a master mode. The various serial rates are shown in Table 7. If the I2C block is to be used in fast mode, bit 3 in AUXR must be set. The user can read but cannot write (write once) to AUXR after setup. 7 AUXR (8EH) - 6 - 5 - 4 - 3
FAST/ STD I2C
2 -
1 -
0 A0
A 12.5kHz bit rate may be used by devices that interface to the I2C-bus via standard I/O port lines which are software driven and slow. 100kHz is usually the maximum bit rate and can be derived from a 16 MHz, 12 MHz, or a 6 MHz oscillator. A variable bit rate (0.5kHz to 62.5kHz) may also be used if Timer 1 is not required for any other purpose while I2C is in a master mode. The frequencies shown in Table 7 are unimportant when I2C is in a slave mode. In the slave modes, I2C will automatically synchronize with any clock frequency up to 100kHz. The Status Register, S1STA: S1STA is an 8-bit read-only special function register. The three least significant bits are always zero. The five most significant bits contain the status code. There are 26 possible status codes. When S1STA contains F8H, no relevant state information is available and no serial interrupt is requested. All other S1STA values correspond to defined I2C states. When each of these states is entered, a serial interrupt is requested (SI = 1). A valid status code is present in S1STA one machine cycle after SI is set by hardware and is still present one machine cycle after SI has been reset by software.
2004 Apr 20
36
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Table 7.
Serial Clock Rates
BIT FREQUENCY (kHz) AT fosc fosc DIVIDED BY 12MHz 94 107 125 150 25 200 400 0.98 < 50.0 0 < 251 15MHz 117 134 156 188 31 250 500 1.22 < 52.1 0 < 250 128 112 96 80 480 60 30 48 x (256- (reload value Timer1)) Reload value Timer 1 in Mode 2.
6 clock mode
CR2 0 0 0 0 1 1 1 1
CR1 0 0 1 1 0 0 1 1
CR0 0 1 0 1 0 1 0 1
3MHz 23 27 31 37 6.25 50 100 0.24<62.5 0 < 255
6MHz 47 54 63 75 12.5 100 200 0.49 < 62.5 0 < 254
8MHz 62.5 71 83.3 100 17 133 267 0.65 < 55.6 0 < 253
12 clock mode BIT FREQUENCY (kHz) AT fosc CR2 0 0 0 0 1 1 1 1 CR1 0 0 1 1 0 0 1 1 CR0 0 1 0 1 0 1 0 1 6MHz 23 27 31 37 6.25 50 100 0.24<62.5 0 < 255 12MHz 47 54 63 75 12.5 100 200 0.49 < 62.5 0 < 254 16MHz 62.5 71 83.3 100 17 133 267 0.65 < 55.6 0 < 253 24MHz 94 107 125 150 25 200 400 0.98 < 50.0 0 < 251 30MHz 117 134 156 188 31 250 500 1.22 < 52.1 0 < 250 256 224 192 160 960 120 60 96 x (256 -(reload value Timer1)) Reload value Timer 1 in Mode 2. fosc DIVIDED BY
NOTES: 1. These frequencies exceed the upper limit of 100kHz of the I2C-bus specification and cannot be used in an I2C-bus application. 2. At fosc = 24 MHz/30 MHz the maximum I2C-bus rate of 100kHz cannot be realized due to the fixed divider rates.
Table 8.
CR2 1 1 1 1 0 0 0 0
Selection of I2C-bus bit rate (Fast mode)
BIT FREQUENCY (kHz) AT fosc CR1 0 0 1 1 0 0 1 1 CR0 0 1 0 1 0 1 0 1 12 MHz 50 3.75 75 100 2001 7.5 3001 4001 16 MHz 66.7 5 100 0 266.71 10 4001 -
NOTES: 1. These bit rates are for "fast-mode" I2C-bus applications and cannot be used for bit rates up to 100 kbit/sec. 2. Serial status register S1STA is a read only register.
2004 Apr 20
37
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
More Information on I2C Operating Modes: The four operating modes are: - Master Transmitter - Master Receiver - Slave Receiver - Slave Transmitter Data transfers in each mode of operation are shown in Figures 28-31. These figures contain the following abbreviations: Abbreviation S SLA R W A A Data P Explanation Start condition 7-bit slave address Read bit (HIGH level at SDA) Write bit (low level at SDA) Acknowledge bit (low level at SDA) Not acknowledge bit (HIGH level at SDA) 8-bit data byte Stop condition
may switch to the master receiver mode by loading S1DAT with SLA+R). Master Receiver Mode: In the master receiver mode, a number of data bytes are received from a slave transmitter (see Figure 29). The transfer is initialized as in the master transmitter mode. When the start condition has been transmitted, the interrupt service routine must load S1DAT with the 7-bit slave address and the data direction bit (SLA+R). The SI bit in S1CON must then be cleared before the serial transfer can continue. When the slave address and the data direction bit have been transmitted and an acknowledgment bit has been received, the serial interrupt flag (SI) is set again, and a number of status codes in S1STA are possible. These are 40H, 48H, or 38H for the master mode and also 68H, 78H, or B0H if the slave mode was enabled (AA = logic 1). The appropriate action to be taken for each of these status codes is detailed in Table 10. ENS1, CR1, and CR0 are not affected by the serial transfer and are not referred to in Table 10. After a repeated start condition (state 10H), I2C may switch to the master transmitter mode by loading S1DAT with SLA+W. Slave Receiver Mode: In the slave receiver mode, a number of data bytes are received from a master transmitter (see Figure 30). To initiate the slave receiver mode, S1ADR and S1CON must be loaded as follows:
AUXR# Auxiliary 8EH - - - - Fast/ Std I2C - - AO
In Figures 28-31, circles are used to indicate when the serial interrupt flag is set. The numbers in the circles show the status code held in the S1STA register. At these points, a service routine must be executed to continue or complete the serial transfer. These service routines are not critical since the serial transfer is suspended until the serial interrupt flag is cleared by software. When a serial interrupt routine is entered, the status code in S1STA is used to branch to the appropriate service routine. For each status code, the required software action and details of the following serial transfer are given in Tables 9-13. Master Transmitter Mode: In the master transmitter mode, a number of data bytes are transmitted to a slave receiver (see Figure 28). Before the master transmitter mode can be entered, S1CON must be initialized as follows: 7 S1CON (D8H) CR2 bit rate 6 ENS1 1 5 STA 0 4 STO 0 3 SI 0 2 AA X 1 CR1 0 CR0
The upper 7 bits are the address to which I2C will respond when addressed by a master. If the LSB (GC) is set, I2C will respond to the general call address (00H); otherwise it ignores the general call address. 7 S1CON (D8H) CR2 X 6 ENS1 1 5 STA 0 4 STO 0 3 SI 0 2 AA 1 1 CR1 X 0 CR0 X
bit rate
CR0, CR1, and CR2 define the serial bit rate. ENS1 must be set to logic 1 to enable I2C. If the AA bit is reset, I2C will not acknowledge its own slave address or the general call address in the event of another device becoming master of the bus. In other words, if AA is reset, SIO0 cannot enter a slave mode. STA, STO, and SI must be reset. The master transmitter mode may now be entered by setting the STA bit using the SETB instruction. The I2C logic will now test the I2C-bus and generate a start condition as soon as the bus becomes free. When a START condition is transmitted, the serial interrupt flag (SI) is set, and the status code in the status register (S1STA) will be 08H. This status code must be used to vector to an interrupt service routine that loads S1DAT with the slave address and the data direction bit (SLA+W). The SI bit in S1CON must then be reset before the serial transfer can continue. When the slave address and the direction bit have been transmitted and an acknowledgment bit has been received, the serial interrupt flag (SI) is set again, and a number of status codes in S1STA are possible. There are 18H, 20H, or 38H for the master mode and also 68H, 78H, or B0H if the slave mode was enabled (AA = logic 1). The appropriate action to be taken for each of these status codes is detailed in Table 9. After a repeated start condition (state 10H). I2C
CR0, CR1, and CR2 do not affect I2C in the slave mode. ENS1 must be set to logic 1 to enable I2C. The AA bit must be set to enable I2C to acknowledge its own slave address or the general call address. STA, STO, and SI must be reset. When S1ADR and S1CON have been initialized, I2C waits until it is addressed by its own slave address followed by the data direction bit which must be logic 0 (W) for I2C to operate in the slave receiver mode. After its own slave address and the W bit have been received, the serial interrupt flag (I) is set and a valid status code can be read from S1STA. This status code is used to vector to an interrupt service routine, and the appropriate action to be taken for each of these status codes is detailed in Table 11. The slave receiver mode may also be entered if arbitration is lost while I2C is in the master mode (see status 68H and 78H). If the AA bit is reset during a transfer, I2C will return a not acknowledge (logic 1) to SDA after the next received data byte. While AA is reset, I2C does not respond to its own slave address or a general call address. However, the I2C-bus is still monitored and address recognition may be resumed at any time by setting AA. This means that the AA bit may be used to temporarily isolate I2C from the I2C-bus.
2004 Apr 20
38
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
MT
SUCCESSFUL TRANSMISSION TO A SLAVE RECEIVER
NEXT TRANSFER STARTED WITH A REPEATED START CONDITION
NOT ACKNOWLEDGE RECEIVED AFTER THE SLAVE ADDRESS
NOT ACKNOWLEDGE RECEIVED AFTER A DATA BYTE
ARBITRATION LOST IN SLAVE ADDRESS OR DATA BYTE
ARBITRATION LOST AND ADDRESSED AS SLAVE
FROM MASTER TO SLAVE
FROM SLAVE TO MASTER
Data
A
ANY NUMBER OF DATA BYTES AND THEIR ASSOCIATED ACKNOWLEDGE BITS
n
THIS NUMBER (CONTAINED IN S1STA) CORRESPONDS TO A DEFINED STATE OF THE I2C BUS. SEE TABLE 9.
Figure 28. Format and States in the Master Transmitter Mode
2004 Apr 20
CCC CCC CCC CCC CCC CCC CCC CCCCCCC CCCCCCC CCCCCCC CCC CCCCC CCCCCCCC C CCC CCCCC CCCCCCCC C
S SLA W A DATA A P 08H 18H 28H S SLA W 10H A P R 20H A P 30H A or A OTHER MST CONTINUES A or A OTHER MST CONTINUES 38H 38H A OTHER MST CONTINUES 68H 78H 80H TO CORRESPONDING STATES IN SLAVE MODE
TO MST/REC MODE ENTRY = MR
CCCC C CC C CCCC CCCC CCC CCCC CCCC CCCC
SU00971
39
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
MR
SUCCESSFUL RECEPTION FROM A SLAVE TRANSMITTER
NEXT TRANSFER STARTED WITH A REPEATED START CONDITION
NOT ACKNOWLEDGE RECEIVED AFTER THE SLAVE ADDRESS
ARBITRATION LOST IN SLAVE ADDRESS OR ACKNOWLEDGE BIT
ARBITRATION LOST AND ADDRESSED AS SLAVE
FROM MASTER TO SLAVE
FROM SLAVE TO MASTER
DATA
A
ANY NUMBER OF DATA BYTES AND THEIR ASSOCIATED ACKNOWLEDGE BITS
n
THIS NUMBER (CONTAINED IN S1STA) CORRESPONDS TO A DEFINED STATE OF THE I2C-BUS. SEE TABLE 10.
2004 Apr 20
CCC CCC CCC CCC CCCCCCC CCCCCCC CCCCCCC CCCCCCCCCC CC C CCCCCCCC CCCCCCCCCC CC C CCCCCCCC
S SLA R A DATA A DATA A P 08H 40H 50H 58H S SLA R 10H A P W 48H TO MST/TRX MODE ENTRY = MT A or A OTHER MST CONTINUES 38H A OTHER MST CONTINUES 68H 78H 80H TO CORRESPONDING STATES IN SLAVE MODE
Figure 29. Format and States in the Master Receiver Mode
40
CCC CCC CCC
A 38H
OTHER MST CONTINUES
CC CCCC CCCCC C CCCC CCCC CCCC
SU00972
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
RECEPTION OF THE OWN SLAVE ADDRESS AND ONE OR MORE DATA BYTES ALL ARE ACKNOWLEDGED.
LAST DATA BYTE RECEIVED IS NOT ACKNOWLEDGED
ARBITRATION LOST AS MST AND ADDRESSED AS SLAVE
RECEPTION OF THE GENERAL CALL ADDRESS AND ONE OR MORE DATA BYTES
LAST DATA BYTE IS NOT ACKNOWLEDGED
ARBITRATION LOST AS MST AND ADDRESSED AS SLAVE BY GENERAL CALL
FROM MASTER TO SLAVE
FROM SLAVE TO MASTER
Data
A
ANY NUMBER OF DATA BYTES AND THEIR ASSOCIATED ACKNOWLEDGE BITS
n
THIS NUMBER (CONTAINED IN S1STA) CORRESPONDS TO A DEFINED STATE OF THE I2C BUS. SEE TABLE 11.
Figure 30. Format and States in the Slave Receiver Mode
2004 Apr 20
CCC CCC CCC CCC CCC CCCCCC CCCCCCC C CCC CCC CCCCCC CCCCCCC C
S SLA W A DATA A DATA SLA A P or S 60H 80H 80H A0H A P or S 88H A 68H
CCC CCC CCC CCC CCC CCCCCC CCCCC C CCC CCC CCCCCC CCCCC C CCC CCC CCCCCC CCCCC C
GENERAL CALL A DATA A DATA A P or S 70H 90H 90H A0H A P or S 98H A 78H
CC C CCCC C CCCC CCCC CCC CCCC CCCC CCCC
SU00973
41
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
RECEPTION OF THE OWN SLAVE ADDRESS AND TRANSMISSION OF ONE OR MORE DATA BYTES
S
SLA
R
A
DATA
A8H
A
ARBITRATION LOST AS MST AND ADDRESSED AS SLAVE
FROM MASTER TO SLAVE
B0H
LAST DATA BYTE TRANSMITTED. SWITCHED TO NOT ADDRESSED SLAVE (AA BIT IN S1CON = "0"
A
All "1"s
FROM SLAVE TO MASTER
C8H
DATA
A
ANY NUMBER OF DATA BYTES AND THEIR ASSOCIATED ACKNOWLEDGE BITS
n
THIS NUMBER (CONTAINED IN S1STA) CORRESPONDS TO A DEFINED STATE OF THE I2C BUS. SEE TABLE 12.
Figure 31. Format and States of the Slave Transmitter Mode
2004 Apr 20
42
CCC CCC CCC
CCCCCCCCCC CC C CCC C C C CCCCCCCCCC CCCCCCCC CC
A DATA A P or S B8H C0H
CCC CCC CCC
CCCCCCCC CCCCCCCC CCCCCCCC
CC CC CCCC CCCC CCCC CCCC
P or S
SU00974
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Table 9.
STATUS CODE (S1STA) 08H 10H
Master Transmitter Mode
STATUS OF THE I2C BUS AND HARDWARE A START condition has been transmitted A repeated START condition h b diti has been transmitted SLA+W has been transmitted; ACK has been received b id APPLICATION SOFTWARE RESPONSE TO/FROM S1DAT STA Load SLA+W Load SLA+W or Load SLA+R Load data byte or no S1DAT action or no S1DAT action or no S1DAT action X X X 0 1 0 1 TO S1CON STO 0 0 0 0 0 1 1 SI 0 0 0 0 0 0 0 AA X X X X X X X SLA+W will be transmitted; ACK bit will be received As above SLA+W will be transmitted; I2C will be switched to MST/REC mode Data byte will be transmitted; ACK bit will be received Repeated START will be transmitted; STOP condition will be transmitted; STO flag will be reset STOP condition followed by a START condition will be transmitted; STO flag will be reset Data byte will be transmitted; ACK bit will be received Repeated START will be transmitted; STOP condition will be transmitted; STO flag will be reset STOP condition followed by a START condition will be transmitted; STO flag will be reset Data byte will be transmitted; ACK bit will be received Repeated START will be transmitted; STOP condition will be transmitted; STO flag will be reset STOP condition followed by a START condition will be transmitted; STO flag will be reset Data byte will be transmitted; ACK bit will be received Repeated START will be transmitted; STOP condition will be transmitted; STO flag will be reset STOP condition followed by a START condition will be transmitted; STO flag will be reset I2C-bus will be released; not addressed slave will be entered A START condition will be transmitted when the bus becomes free NEXT ACTION TAKEN BY AND I2C HARDWARE
18H
20H
SLA+W has been transmitted; NOT ACK hb id has been received
Load data byte or no S1DAT action or no S1DAT action or no S1DAT action
0 1 0 1
0 0 1 1
0 0 0 0
X X X X
28H
Data byte in S1DAT has been transmitted; ACK hb id has been received
Load data byte or no S1DAT action or no S1DAT action or no S1DAT action
0 1 0 1
0 0 1 1
0 0 0 0
X X X X
30H
Data byte in S1DAT has been transmitted; NOT ACK h b id has been received
Load data byte or no S1DAT action or no S1DAT action or no S1DAT action
0 1 0 1
0 0 1 1
0 0 0 0
X X X X
38H
Arbitration lost in SLA+R/W or Data b D bytes
No S1DAT action or No S1DAT action
0 1
0 0
0 0
X X
2004 Apr 20
43
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Table 10.
STATUS CODE (S1STA) 08H 10H
Master Receiver Mode
STATUS OF THE I2C-BUS AND HARDWARE A START condition has been transmitted A repeated START condition h b diti has been transmitted Arbitration lost in NOT ACK bit APPLICATION SOFTWARE RESPONSE TO/FROM S1DAT STA Load SLA+R Load SLA+R or Load SLA+W No S1DAT action or No S1DAT action X X X 0 1 0 0 1 0 1 TO S1CON STO 0 0 0 0 0 0 0 0 1 1 SI 0 0 0 0 0 0 0 0 0 0 AA X X X X X 0 1 X X X SLA+R will be transmitted; ACK bit will be received As above SLA+W will be transmitted; I2C will be switched to MST/TRX mode I2C-bus will be released; I2C will enter a slave mode A START condition will be transmitted when the bus becomes free Data byte will be received; NOT ACK bit will be returned Data byte will be received; ACK bit will be returned Repeated START condition will be transmitted STOP condition will be transmitted; STO flag will be reset STOP condition followed by a START condition will be transmitted; STO flag will be reset Data byte will be received; NOT ACK bit will be returned Data byte will be received; ACK bit will be returned Repeated START condition will be transmitted STOP condition will be transmitted; STO flag will be reset STOP condition followed by a START condition will be transmitted; STO flag will be reset NEXT ACTION TAKEN BY I2C HARDWARE
38H
40H
SLA+R has been transmitted; ACK has b id been received SLA+R has been transmitted; NOT ACK t itt d has been received
No S1DAT action or no S1DAT action No S1DAT action or no S1DAT action or no S1DAT action
48H
50H
Data byte has been received; ACK has been d returned Data byte has been received; NOT ACK h id has been returned
Read data byte or read data byte Read data byte or read data byte or read data byte
0 0 1 0 1
0 0 0 1 1
0 0 0 0 0
0 1 X X X
58H
2004 Apr 20
44
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Table 11.
STATUS CODE (S1STA) 60H
Slave Receiver Mode
STATUS OF THE I2C BUS AND HARDWARE Own SLA+W has been received; ACK hb d has been returned Arbitration lost in SLA+R/W as master; Own SLA+W has b id been received, ACK returned General call address (00H) has been received; ACK has received been returned Arbitration lost in SLA+R/W as master; General call address has been received, received ACK has been returned Previously addressed with own SLV address; DATA has b id been received; ACK has been returned Previously addressed with own SLA; DATA b byte h b has been received; NOT ACK has been returned APPLICATION SOFTWARE RESPONSE TO/FROM S1DAT STA No S1DAT action or no S1DAT action No S1DAT action or X X X TO S1CON STO 0 0 0 SI 0 0 0 AA 0 1 0 Data byte will be received and NOT ACK will be returned Data byte will be received and ACK will be returned Data byte will be received and NOT ACK will be returned Data byte will be received and ACK will be returned Data byte will be received and NOT ACK will be returned Data byte will be received and ACK will be returned Data byte will be received and NOT ACK will be returned Data byte will be received and ACK will be returned Data byte will be received and NOT ACK will be returned Data byte will be received and ACK will be returned Switched to not addressed SLV mode; no recognition of own SLA or General call address Switched to not addressed SLV mode; Own SLA will be recognized; General call address will be recognized if S1ADR.0 = logic 1 Switched to not addressed SLV mode; no recognition of own SLA or General call address. A START condition will be transmitted when the bus becomes free Switched to not addressed SLV mode; Own SLA will be recognized; General call address will be recognized if S1ADR.0 = logic 1. A START condition will be transmitted when the bus becomes free. Data byte will be received and NOT ACK will be returned Data byte will be received and ACK will be returned Switched to not addressed SLV mode; no recognition of own SLA or General call address Switched to not addressed SLV mode; Own SLA will be recognized; General call address will be recognized if S1ADR.0 = logic 1 Switched to not addressed SLV mode; no recognition of own SLA or General call address. A START condition will be transmitted when the bus becomes free Switched to not addressed SLV mode; Own SLA will be recognized; General call address will be recognized if S1ADR.0 = logic 1. A START condition will be transmitted when the bus becomes free. NEXT ACTION TAKEN BY I2C HARDWARE
68H
no S1DAT action No S1DAT action or no S1DAT action No S1DAT action or
X X X X
0 0 0 0
0 0 0 0
1 0 1 0
70H
78H
no S1DAT action Read data byte or
X X
0 0
0 0
1 0
80H
read data byte Read data byte or read data byte or
X 0 0
0 0 0
0 0 0
1 0 1
88H
read data byte or
1
0
0
0
read data byte
1
0
0
1
90H
Previously addressed with General Call; DATA byte has been received; ACK h id has been returned Previously addressed with General Call; DATA b hb byte has been received; NOT ACK has been returned
Read data byte or
X
0
0
0
read data byte Read data byte or read data byte or
X 0 0
0 0 0
0 0 0
1 0 1
98H
read data byte or
1
0
0
0
read data byte
1
0
0
1
2004 Apr 20
45
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Table 11.
STATUS CODE (S1STA) A0H
Slave Receiver Mode (Continued)
STATUS OF THE I2C BUS AND HARDWARE A STOP condition or repeated START di i has been condition h b received while still addressed as SLV/REC or SLV/TRX APPLICATION SOFTWARE RESPONSE TO/FROM S1DAT STA No STDAT action or No STDAT action or 0 0 TO S1CON STO 0 0 SI 0 0 AA 0 1 Switched to not addressed SLV mode; no recognition of own SLA or General call address Switched to not addressed SLV mode; Own SLA will be recognized; General call address will be recognized if S1ADR.0 = logic 1 Switched to not addressed SLV mode; no recognition of own SLA or General call address. A START condition will be transmitted when the bus becomes free Switched to not addressed SLV mode; Own SLA will be recognized; General call address will be recognized if S1ADR.0 = logic 1. A START condition will be transmitted when the bus becomes free. NEXT ACTION TAKEN BY I2C HARDWARE
No STDAT action or
1
0
0
0
No STDAT action
1
0
0
1
Table 12.
STATUS CODE (S1STA) A8H
Slave Transmitter Mode
STATUS OF THE I2C BUS AND HARDWARE Own SLA+R has been received; ACK hb d has been returned Arbitration lost in SLA+R/W as master; Own SLA+R has been received, ACK has been returned Data byte in S1DAT has been transmitted; ACK has been received Data byte in S1DAT has been transmitted; NOT ACK h b has been received APPLICATION SOFTWARE RESPONSE TO/FROM S1DAT STA Load data byte or load data byte Load data byte or X X X TO S1CON STO 0 0 0 SI 0 0 0 AA 0 1 0 Last data byte will be transmitted and ACK bit will be received Data byte will be transmitted; ACK will be received Last data byte will be transmitted and ACK bit will be received Data byte will be transmitted; ACK bit will be received Last data byte will be transmitted and ACK bit will be received Data byte will be transmitted; ACK bit will be received Switched to not addressed SLV mode; no recognition of own SLA or General call address Switched to not addressed SLV mode; Own SLA will be recognized; General call address will be recognized if S1ADR.0 = logic 1 Switched to not addressed SLV mode; no recognition of own SLA or General call address. A START condition will be transmitted when the bus becomes free Switched to not addressed SLV mode; Own SLA will be recognized; General call address will be recognized if S1ADR.0 = logic 1. A START condition will be transmitted when the bus becomes free. Switched to not addressed SLV mode; no recognition of own SLA or General call address Switched to not addressed SLV mode; Own SLA will be recognized; General call address will be recognized if S1ADR.0 = logic 1 Switched to not addressed SLV mode; no recognition of own SLA or General call address. A START condition will be transmitted when the bus becomes free Switched to not addressed SLV mode; Own SLA will be recognized; General call address will be recognized if S1ADR.0 = logic 1. A START condition will be transmitted when the bus becomes free. NEXT ACTION TAKEN BY I2C HARDWARE
B0H
load data byte Load data byte or load data byte No S1DAT action or no S1DAT action or
X X X 0 0
0 0 0 0 0
0 0 0 0 0
1 0 1 01 1
B8H
C0H
no S1DAT action or
1
0
0
0
no S1DAT action
1
0
0
1
C8H
Last data byte in S1DAT has been id 0) transmitted (AA = 0); ACK has been received
No S1DAT action or no S1DAT action or
0 0
0 0
0 0
0 1
no S1DAT action or
1
0
0
0
no S1DAT action
1
0
0
1
2004 Apr 20
46
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Table 13.
STATUS CODE (S1STA) F8H
Miscellaneous States
STATUS OF THE I2C BUS AND HARDWARE APPLICATION SOFTWARE RESPONSE TO/FROM S1DAT STA No S1DAT action TO S1CON STO SI AA Wait or proceed current transfer NEXT ACTION TAKEN BY I2C HARDWARE
No relevant state information available; SI = 0 Bus error during MST or selected slave modes, due to an illegal START or STOP condition. State 00H can also occur when interference causes I2C to enter an undefined state.
No S1CON action
00H
No S1DAT action
0
1
0
X
Only the internal hardware is affected in the MST or addressed SLV modes. In all cases, the bus is released and I2C is switched to the not addressed SLV mode. STO is reset.
Slave Transmitter Mode: In the slave transmitter mode, a number of data bytes are transmitted to a master receiver (see Figure 31). Data transfer is initialized as in the slave receiver mode. When S1ADR and S1CON have been initialized, I2C waits until it is addressed by its own slave address followed by the data direction bit which must be logic 1 (R) for the I2C to operate in the slave transmitter mode. After its own slave address and the R bit have been received, the serial interrupt flag (SI) is set and a valid status code can be read from S1STA. This status code is used to vector to an interrupt service routine, and the appropriate action to be taken for each of these status codes is detailed in Table 12. The slave transmitter mode may also be entered if arbitration is lost while I2C is in the master mode (see state B0H). If the AA bit is reset during a transfer, I2C will transmit the last byte of the transfer and enter state C0H or C8H. I2C is switched to the not addressed slave mode and will ignore the master receiver if it continues the transfer. Thus the master receiver receives all 1s as serial data. While AA is reset, I2C does not respond to its own slave address or a general call address. However, the I2C-bus is still monitored, and address recognition may be resumed at any time by setting AA. This means that the AA bit may be used to temporarily isolate I2C from the I2C-bus. Miscellaneous States: There are two S1STA codes that do not correspond to a defined I2C hardware state (see Table 13). These are discussed below. S1STA = F8H: This status code indicates that no relevant information is available because the serial interrupt flag, SI, is not yet set. This occurs between other states and when I2C is not involved in a serial transfer. S1STA = 00H: This status code indicates that a bus error has occurred during an I2C serial transfer. A bus error is caused when a START or STOP condition occurs at an illegal position in the format frame. Examples of such illegal positions are during the serial transfer of an address byte, a data byte, or an acknowledge bit. A bus error may also be caused when external interference disturbs the internal I2C signals. When a bus error occurs, SI is set. To recover from a bus error, the STO flag must be set and SI must be cleared. This causes I2C to enter the "not addressed" slave mode (a defined state) and to clear
the STO flag (no other bits in S1CON are affected). The SDA and SCL lines are released (a STOP condition is not transmitted). Some Special Cases: The I2C hardware has facilities to handle the following special cases that may occur during a serial transfer: Simultaneous Repeated START Conditions from Two Masters A repeated START condition may be generated in the master transmitter or master receiver modes. A special case occurs if another master simultaneously generates a repeated START condition (see Figure 32). Until this occurs, arbitration is not lost by either master since they were both transmitting the same data. If the I2C hardware detects a repeated START condition on the I2C-bus before generating a repeated START condition itself, it will release the bus, and no interrupt request is generated. If another master frees the bus by generating a STOP condition, I2C will transmit a normal START condition (state 08H), and a retry of the total serial data transfer can commence. DATA TRANSFER AFTER LOSS OF ARBITRATION Arbitration may be lost in the master transmitter and master receiver modes (see Figure 24). Loss of arbitration is indicated by the following states in S1STA; 38H, 68H, 78H, and B0H (see Figures 28 and 29). If the STA flag in S1CON is set by the routines which service these states, then, if the bus is free again, a START condition (state 08H) is transmitted without intervention by the CPU, and a retry of the total serial transfer can commence. FORCED ACCESS TO THE I2C-BUS In some applications, it may be possible for an uncontrolled source to cause a bus hang-up. In such situations, the problem may be caused by interference, temporary interruption of the bus or a temporary short-circuit between SDA and SCL. If an uncontrolled source generates a superfluous START or masks a STOP condition, then the I2C-bus stays busy indefinitely. If the STA flag is set and bus access is not obtained within a reasonable amount of time, then a forced access to the I2C-bus is possible. This is achieved by setting the STO flag while the STA flag is still set. No STOP condition is transmitted. The I2C hardware behaves as if a STOP condition was received and is able to transmit a START condition. The STO flag is cleared by hardware (see Figure 33).
2004 Apr 20
47
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
S
SLA
W
A
DATA
A
S
BOTH MASTERS CONTINUE WITH SLA TRANSMISSION
08H
18H
28H
OTHER MASTER SENDS REPEATED START CONDITION EARLIER
SU00975
Figure 32. Simultaneous Repeated START Conditions from 2 Masters
TIME OUT
STA FLAG
SDA LINE
SCL LINE
START CONDITION
SU00976
Figure 33. Forced Access to a Busy I2C-BUS OBSTRUCTED BY A LOW LEVEL ON SCL OR SDA An I2C-bus hang-up occurs if SDA or SCL is pulled LOW by an uncontrolled source. If the SCL line is obstructed (pulled LOW) by a device on the bus, no further serial transfer is possible, and the I2C hardware cannot resolve this type of problem. When this occurs, the problem must be resolved by the device that is pulling the SCL bus line LOW. If the SDA line is obstructed by another device on the bus (e.g., a slave device out of bit synchronization), the problem can be solved by transmitting additional clock pulses on the SCL line (see Figure 34). The I2C hardware transmits additional clock pulses when the STA flag is set, but no START condition can be generated because the SDA line is pulled LOW while the I2C-bus is considered free. The I2C hardware attempts to generate a START condition after every two additional clock pulses on the SCL line. When the SDA line is eventually released, a normal START condition is transmitted, state 08H is entered, and the serial transfer continues. If a forced bus access occurs or a repeated START condition is transmitted while SDA is obstructed (pulled LOW), the I2C hardware
I2C-bus
performs the same action as described above. In each case, state 08H is entered after a successful START condition is transmitted and normal serial transfer continues. Note that the CPU is not involved in solving these bus hang-up problems. BUS ERROR A bus error occurs when a START or STOP condition is present at an illegal position in the format frame. Examples of illegal positions are during the serial transfer of an address byte, a data or an acknowledge bit. The I2C hardware only reacts to a bus error when it is involved in a serial transfer either as a master or an addressed slave. When a bus error is detected, I2C immediately switches to the not addressed slave mode, releases the SDA and SCL lines, sets the interrupt flag, and loads the status register with 00H. This status code may be used to vector to a service routine which either attempts the aborted serial transfer again or simply recovers from the error condition as shown in Table 13.
2004 Apr 20
48
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
STA FLAG (2) SDA LINE (1) (1) (3)
SCL LINE
START CONDITION
(1) Unsuccessful attempt to send a Start condition (2) SDA line released (3) Successful attempt to send a Start condition; state 08H is entered
SU00977
Figure 34. Recovering from a Bus Obstruction Caused by a Low Level on SDA Software Examples of I2C Service Routines: This section consists of a software example for: - Initialization of I2C after a RESET - Entering the I2C interrupt routine - The 26 state service routines for the - Master transmitter mode - Master receiver mode - Slave receiver mode - Slave transmitter mode INITIALIZATION In the initialization routine, I2C is enabled for both master and slave modes. For each mode, a number of bytes of internal data RAM are allocated to the SIO to act as either a transmission or reception buffer. In this example, 8 bytes of internal data RAM are reserved for different purposes. The data memory map is shown in Figure 35. The initialization routine performs the following functions: - S1ADR is loaded with the part's own slave address and the general call bit (GC) - P1.6 and P1.7 bit latches are loaded with logic 1s - RAM location HADD is loaded with the high-order address byte of the service routines - The I2C interrupt enable and interrupt priority bits are set - The slave mode is enabled by simultaneously setting the ENS1 and AA bits in S1CON and the serial clock frequency (for master modes) is defined by loading CR0 and CR1 in S1CON. The master routines must be started in the main program. The I2C hardware now begins checking the I2C-bus for its own slave address and general call. If the general call or the own slave address is detected, an interrupt is requested and S1STA is loaded with the appropriate state information. The following text describes a fast method of branching to the appropriate service routine. I2C INTERRUPT ROUTINE When the I2C interrupt is entered, the PSW is first pushed on the stack. Then S1STA and HADD (loaded with the high-order address byte of the 26 service routines by the initialization routine) are pushed on to the stack. S1STA contains a status code which is the lower byte of one of the 26 service routines. The next instruction is RET, which is the return from subroutine instruction. When this instruction is executed, the HIGH and LOW order address bytes are popped from stack and loaded into the program counter. The next instruction to be executed is the first instruction of the state service routine. Seven bytes of program code (which execute in eight machine cycles) are required to branch to one of the 26 state service routines. SI PUSH PSW PUSH S1STA PUSH HADD RET Save PSW Push status code (low order address byte) Push HIGH order address byte Jump to state service routine
The state service routines are located in a 256-byte page of program memory. The location of this page is defined in the initialization routine. The page can be located anywhere in program memory by loading data RAM register HADD with the page number. Page 01 is chosen in this example, and the service routines are located between addresses 0100H and 01FFH. THE STATE SERVICE ROUTINES The state service routines are located 8 bytes from each other. Eight bytes of code are sufficient for most of the service routines. A few of the routines require more than 8 bytes and have to jump to other locations to obtain more bytes of code. Each state routine is part of the I2C interrupt routine and handles one of the 26 states. It ends with a RETI instruction which causes a return to the main program.
2004 Apr 20
49
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
SPECIAL FUNCTION REGISTERS
S1ADR S1DAT S1STA S1CON CR2 ENS1 STA ST0 SI 0 AA 0 CR!
GC
DB DA
0 CR0
D9 D8
PSW
D0
IPO
PS1
B8
IEN0
EA
ES1
AB
P1
P1.7
P1.6
90
80
INTERNAL DATA RAM 7F
BACKUP NUMBYTMST SLA HADD
ORIGINAL VALUE OF NUMBYTMST NUMBER OF BYTES AS MASTER SLA+R/W TO BE TRANSMITTED TO SLA HIGHER ADDRESS BYTE INTERRUPT ROUTINE SLAVE TRANSMITTER DATA RAM
53 52 51 50 4F
STD SLAVE RECEIVER DATA RAM SRD MASTER RECEIVER DATA RAM MRD MASTER TRANSMITTER DATA RAM MTD
48
40
38
30
R1 R0
19 18
00
SU00978
Figure 35.
I 2C
Data Memory Map
2004 Apr 20
50
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
MASTER TRANSMITTER AND MASTER RECEIVER MODES The master mode is entered in the main program. To enter the master transmitter mode, the main program must first load the internal data RAM with the slave address, data bytes, and the number of data bytes to be transmitted. To enter the master receiver mode, the main program must first load the internal data RAM with the slave address and the number of data bytes to be received. The R/W bit determines whether I2C operates in the master transmitter or master receiver mode. Master mode operation commences when the STA bit in S1CION is set by the SETB instruction and data transfer is controlled by the master state service routines in accordance with Table 9, Table 10, Figure 28, and Figure 29. In the example below, 4 bytes are transferred. There is no repeated START condition. In the event of lost arbitration, the transfer is restarted when the bus becomes free. If a bus error occurs, the I2C-bus is released and I2C enters the not selected slave receiver mode. If a slave device returns a not acknowledge, a STOP condition is generated. A repeated START condition can be included in the serial transfer if the STA flag is set instead of the STO flag in the state service routines vectored to by status codes 28H and 58H. Additional software must be written to determine which data is transferred after a repeated START condition. SLAVE TRANSMITTER AND SLAVE RECEIVER MODES After initialization, I2C continually tests the I2C-bus and branches to one of the slave state service routines if it detects its own slave address or the general call address (see Table 11, Table 12, Figure 30, and Figure 31). If arbitration was lost while in the master mode, the master mode is restarted after the current transfer. If a bus error
occurs, the I2C-bus is released and I2C enters the not selected slave receiver mode. In the slave receiver mode, a maximum of 8 received data bytes can be stored in the internal data RAM. A maximum of 8 bytes ensures that other RAM locations are not overwritten if a master sends more bytes. If more than 8 bytes are transmitted, a not acknowledge is returned, and I2C enters the not addressed slave receiver mode. A maximum of one received data byte can be stored in the internal data RAM after a general call address is detected. If more than one byte is transmitted, a not acknowledge is returned and I2C enters the not addressed slave receiver mode. In the slave transmitter mode, data to be transmitted is obtained from the same locations in the internal data RAM that were previously loaded by the main program. After a not acknowledge has been returned by a master receiver device, I2C enters the not addressed slave mode. ADAPTING THE SOFTWARE FOR DIFFERENT APPLICATIONS The following software example shows the typical structure of the interrupt routine including the 26 state service routines and may be used as a base for user applications. If one or more of the four modes are not used, the associated state service routines may be removed but, care should be taken that a deleted routine can never be invoked. This example does not include any time-out routines. In the slave modes, time-out routines are not very useful since, in these modes, I2C behaves essentially as a passive device. In the master modes, an internal timer may be used to cause a time-out if a serial transfer is not complete after a defined period of time. This time period is defined by the system connected to the I2C-bus.
2004 Apr 20
51
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
00D8 00D9 00DA 00DB 00A8 00B8
!******************************************************************************************************** ! SI01 EQUATE LIST !******************************************************************************************************** !******************************************************************************************************** ! LOCATIONS OF THE SI01 SPECIAL FUNCTION REGISTERS !******************************************************************************************************** S1CON -0xd8 S1STA -0xd9 S1DAT -0xda S1ADR -0xdb IEN0 IP0 -0xa8 -02b8
!******************************************************************************************************** ! BIT LOCATIONS !******************************************************************************************************** 00DD 00BD STA SI01HP -0xdd -0xbd ! STA bit in S1CON ! IP0, SI01 Priority bit
00D5 00C5 00C1 00E5
!******************************************************************************************************** ! IMMEDIATE DATA TO WRITE INTO REGISTER S1CON !******************************************************************************************************** ENS1_NOTSTA_STO_NOTSI_AA_CR0 -0xd5 ! Generates STOP ! (CR0 = 100kHz) ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 -0xc5 ! Releases BUS and ! ACK ENS1_NOTSTA_NOTSTO_NOTSI_NOTAA_CR0 -0xc1 ! Releases BUS and ! NOT ACK ENS1_STA_NOTSTO_NOTSI_AA_CR0 -0xe5 ! Releases BUS and ! set STA !******************************************************************************************************** ! GENERAL IMMEDIATE DATA !******************************************************************************************************** OWNSLA -0x31 ! Own SLA+General Call ! must be written into S1ADR ENSI01 -0xa0 ! EA+ES1, enable I2C interrupt ! must be written into IEN0 PAG1 -0x01 ! select PAG1 as HADD SLAW -0xc0 ! SLA+W to be transmitted SLAR -0xc1 ! SLA+R to be transmitted SELRB3 -0x18 ! Select Register Bank 3 !******************************************************************************************************** ! LOCATIONS IN DATA RAM !******************************************************************************************************** MTD -0x30 ! MST/TRX/DATA base address MRD -0x38 ! MST/REC/DATA base address SRD -0x40 ! SLV/REC/DATA base address STD -0x48 ! SLV/TRX/DATA base address BACKUP NUMBYTMST SLA HADD -0x53 -0x52 -0x51 -0x50 ! Backup from NUMBYTMST ! To restore NUMBYTMST in case ! of an Arbitration Loss. ! Number of bytes to transmit ! or receive as MST. ! Contains SLA+R/W to be ! transmitted. ! High Address byte for STATE 0 ! till STATE 25.
0031 00A0 0001 00C0 00C1 0018
0030 0038 0040 0048 0053 0052 0051 0050
2004 Apr 20
52
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
0000
4100
!******************************************************************************************************** ! INITIALIZATION ROUTINE ! Example to initialize IIC Interface as slave receiver or slave transmitter and ! start a MASTER TRANSMIT or a MASTER RECEIVE function. 4 bytes will be transmitted or received. !******************************************************************************************************** .sect strt .base 0x00 ajmp INIT ! RESET .sect .base INIT: initial 0x200 mov setb setb mov orl clr mov S1ADR,#OWNSLA ! Load own SLA + enable ! general call recognition ! P1.6 High level. ! P1.7 High level.
0200 0203 0205 0207 020A 020D 020F
75DB31 D296 D297 755001 43A8A0 C2BD 75D8C5
P1(6) P1(7) HADD,#PAG1 IEN0,#ENSI01 ! Enable SI01 interrupt SI01HP ! SI01 interrupt low priority S1CON, #ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! Initialize SLV funct.
!******************************************************************************************************** !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! START MASTER TRANSMIT FUNCTION !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 0212 0215 0218 755204 7551C0 D2DD mov mov setb NUMBYTMST,#0x4 SLA,#SLAW STA ! Transmit 4 bytes. ! SLA+W, Transmit funct. ! set STA in S1CON
021A 021D 0220
755204 7551C1 D2DD
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! START MASTER RECEIVE FUNCTION !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - mov NUMBYTMST,#0x4 ! Receive 4 bytes. mov SLA,#SLAR ! SLA+R, Receive funct. setb STA ! set STA in S1CON
!******************************************************************************************************** ! SI01 INTERRUPT ROUTINE !******************************************************************************************************** .sect intvec ! SI01 interrupt vector .base 0x00 ! S1STA and HADD are pushed onto the stack. ! They serve as return address for the RET instruction. ! The RET instruction sets the Program Counter to address HADD, ! S1STA and jumps to the right subroutine. 002B 002D 002F 0031 C0D0 C0D9 C050 22 push psw push S1STA push HADD ret ! save psw
! JMP to address HADD,S1STA.
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 00, Bus error. ! ACTION : Enter not addressed SLV mode and release bus. STO reset. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect st0 .base 0x100 0100 0103 0105 75D8D5 D0D0 32 mov pop reti S1CON,#ENS1_NOTSTA_STO_NOTSI_AA_CR0 ! clr SI ! set STO,AA psw
2004 Apr 20
53
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
!******************************************************************************************************** !******************************************************************************************************** ! MASTER STATE SERVICE ROUTINES !******************************************************************************************************** ! State 08 and State 10 are both for MST/TRX and MST/REC. ! The R/W bit decides whether the next state is within ! MST/TRX mode or within MST/REC mode. !******************************************************************************************************** !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 08, A, START condition has been transmitted. ! ACTION : SLA+R/W are transmitted, ACK bit is received. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect mts8 .base 0x108 0108 010B 010E 8551DA 75D8C5 01A0 S1DAT,SLA ! Load SLA+R/W S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI ajmp INITBASE1 !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 10, A repeated START condition has been ! transmitted. ! ACTION : SLA+R/W are transmitted, ACK bit is received. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect mts10 .base 0x110 0110 0113 010E 8551DA 75D8C5 01A0 .sect ibase1 .base 0xa0 INITBASE1: S1DAT,SLA ! Load SLA+R/W S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI ajmp INITBASE1 mov mov mov mov
00A0 00A3 00A5 00A7 00AA 00AC
75D018 7930 7838 855253 D0D0 32
mov mov mov mov pop reti
psw,#SELRB3 r1,#MTD r0,#MRD BACKUP,NUMBYTMST psw
! Save initial value
!******************************************************************************************************** !******************************************************************************************************** ! MASTER TRANSMITTER STATE SERVICE ROUTINES !******************************************************************************************************** !******************************************************************************************************** !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 18, Previous state was STATE 8 or STATE 10, SLA+W have been transmitted, ! ACK has been received. ! ACTION : First DATA is transmitted, ACK bit is received. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect mts18 .base 0x118 0118 011B 011D 75D018 87DA 01B5 mov psw,#SELRB3 mov S1DAT,@r1 ajmp CON
2004 Apr 20
54
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 20, SLA+W have been transmitted, NOT ACK has been received ! ACTION : Transmit STOP condition. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect mts20 .base 0x120 0120 0123 0125 75D8D5 D0D0 32 mov pop reti S1CON,#ENS1_NOTSTA_STO_NOTSI_AA_CR0 ! set STO, clr SI psw
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 28, DATA of S1DAT have been transmitted, ACK received. ! ACTION : If Transmitted DATA is last DATA then transmit a STOP condition, ! else transmit next DATA. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect mts28 .base 0x128 0128 012B 012E D55285 75D8D5 01B9 .sect mts28sb .base 0x0b0 NOTLDAT1: CON: djnz mov NUMBYTMST,NOTLDAT1 ! JMP if NOT last DATA S1CON,#ENS1_NOTSTA_STO_NOTSI_AA_CR0 ! clr SI, set AA ajmp RETmt
00B0 00B3 00B5 00B8 00B9 00BB
75D018 87DA 75D8C5 09 D0D0 32
mov mov mov
RETmt
inc pop reti !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 30, DATA of S1DAT have been transmitted, NOT ACK received. ! ACTION : Transmit a STOP condition. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect mts30 .base 0x130 : mov pop reti S1CON,#ENS1_NOTSTA_STO_NOTSI_AA_CR0 ! set STO, clr SI psw
psw,#SELRB3 S1DAT,@r1 S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA r1 psw
0130 0133 0135
75D8D5 D0D0 32
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 38, Arbitration lost in SLA+W or DATA. ! ACTION : Bus is released, not addressed SLV mode is entered. ! A new START condition is transmitted when the IIC-bus is free again. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect mts38 .base 0x138 0138 013B 013E 75D8E5 855352 01B9 mov S1CON,#ENS1_STA_NOTSTO_NOTSI_AA_CR0 mov NUMBYTMST,BACKUP ajmp RETmt
2004 Apr 20
55
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
!******************************************************************************************************** !******************************************************************************************************** ! MASTER RECEIVER STATE SERVICE ROUTINES !******************************************************************************************************** !******************************************************************************************************** !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 40, Previous state was STATE 08 or STATE 10, ! SLA+R have been transmitted, ACK received. ! ACTION : DATA will be received, ACK returned. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect mts40 .base 0x140 0140 0143 75D8C5 D0D0 32 mov pop reti S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr STA, STO, SI set AA psw
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 48, SLA+R have been transmitted, NOT ACK received. ! ACTION : STOP condition will be generated. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect mts48 .base 0x148 0148 014B 014D 75D8D5 D0D0 32 STOP: mov pop reti S1CON,#ENS1_NOTSTA_STO_NOTSI_AA_CR0 ! set STO, clr SI psw
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 50, DATA have been received, ACK returned. ! ACTION : Read DATA of S1DAT. ! DATA will be received, if it is last DATA then NOT ACK will be returned else ACK will be returned. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect mrs50 .base 0x150 0150 0153 0155 75D018 A6DA 01C0 .sect .base 00C0 00C3 00C6 00C8 00CB 00CC 00CE D55205 75D8C1 8003 75D8C5 08 D0D0 32 REC1: mrs50s 0xc0 djnz mov NUMBYTMST,NOTLDAT2 S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_NOTAA_CR0 ! clr SI,AA sjmp RETmr mov S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA inc r0 pop psw reti mov psw,#SELRB3 mov @r0,S1DAT ajmp REC1
! Read received DATA
NOTLDAT2: RETmr:
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 58, DATA have been received, NOT ACK returned. ! ACTION : Read DATA of S1DAT and generate a STOP condition. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect mrs58 .base 0x158 0158 015B 015D 75D018 A6DA 80E9 mov psw,#SELRB3 mov @R0,S1DAT sjmp STOP 56
2004 Apr 20
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
!******************************************************************************************************** !******************************************************************************************************** ! SLAVE RECEIVER STATE SERVICE ROUTINES !******************************************************************************************************** !******************************************************************************************************** !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 60, Own SLA+W have been received, ACK returned. ! ACTION : DATA will be received and ACK returned. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect srs60 .base 0x160 mov S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA mov psw,#SELRB3 ajmp INITSRD .sect insrd .base 0xd0 INITSRD: mov mov pop reti r0,#SRD r1,#8 psw
0160 0163 0166
75D8C5 75D018 01D0
00D0 00D2 00D4 00D6
7840 7908 D0D0 32
0168 016B 016E
75D8E5 75D018 01D0
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 68, Arbitration lost in SLA and R/W as MST ! Own SLA+W have been received, ACK returned ! ACTION : DATA will be received and ACK returned. ! STA is set to restart MST mode after the bus is free again. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect srs68 .base 0x168 mov S1CON,#ENS1_STA_NOTSTO_NOTSI_AA_CR0 mov psw,#SELRB3 ajmp INITSRD !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 70, General call has been received, ACK returned. ! ACTION : DATA will be received and ACK returned. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect srs70 .base 0x170 mov S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA mov psw,#SELRB3 ! Initialize SRD counter ajmp initsrd !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 78, Arbitration lost in SLA+R/W as MST. ! General call has been received, ACK returned. ! ACTION : DATA will be received and ACK returned. ! STA is set to restart MST mode after the bus is free again. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect srs78 .base 0x178 mov S1CON,#ENS1_STA_NOTSTO_NOTSI_AA_CR0 mov psw,#SELRB3 ! Initialize SRD counter ajmp INITSRD
0170 0173 0176
75D8C5 75D018 01D0
0178 017B 017E
75D8E5 75D018 01D0
2004 Apr 20
57
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 80, Previously addressed with own SLA. DATA received, ACK returned. ! ACTION : Read DATA. ! IF received DATA was the last ! THEN superfluous DATA will be received and NOT ACK returned ELSE next DATA will be received and ACK returned. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect srs80 .base 0x180 0180 0183 0185 75D018 A6DA 01D8 .sect .base 00D8 00DA 00DD 00DF 00E0 00E3 00E4 00E6 D906 75D8C1 D0D0 32 75D8C5 08 D0D0 32 REC2: LDAT: srs80s 0xd8 djnz mov pop reti mov inc pop reti r1,NOTLDAT3 S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_NOTAA_CR0 ! clr SI,AA psw S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA r0 psw mov psw,#SELRB3 mov @r0,S1DAT ajmp REC2
! Read received DATA
NOTLDAT3:
RETsr:
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 88, Previously addressed with own SLA. DATA received NOT ACK returned. ! ACTION : No save of DATA, Enter NOT addressed SLV mode. ! Recognition of own SLA. General call recognized, if S1ADR. 0-1. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect srs88 .base 0x188 0188 018B 75D8C5 01E4 S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA ajmp RETsr !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 90, Previously addressed with general call. ! DATA has been received, ACK has been returned. ! ACTION : Read DATA. After General call only one byte will be received with ACK ! the second DATA will be received with NOT ACK. ! DATA will be received and NOT ACK returned. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect srs90 .base 0x190 0190 0193 0195 75D018 A6DA 01DA mov psw,#SELRB3 mov @r0,S1DAT ! Read received DATA ajmp LDAT !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : 98, Previously addressed with general call. ! DATA has been received, NOT ACK has been returned. ! ACTION : No save of DATA, Enter NOT addressed SLV mode. Recognition of own SLA. General call recognized, if S1ADR. 0-1. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect srs98 .base 0x198 mov pop reti S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA psw mov
0198 019B 019D
75D8C5 D0D0 32
2004 Apr 20
58
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : A0, A STOP condition or repeated START has been received, ! while still addressed as SLV/REC or SLV/TRX. ! ACTION : No save of DATA, Enter NOT addressed SLV mode. ! Recognition of own SLA. General call recognized, if S1ADR. 0-1. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect srsA0 .base 0x1a0 01A0 01A3 01A5 75D8C5 D0D0 32 mov pop reti S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA psw
!******************************************************************************************************** !******************************************************************************************************** ! SLAVE TRANSMITTER STATE SERVICE ROUTINES !******************************************************************************************************** !******************************************************************************************************** !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : A8, Own SLA+R received, ACK returned. ! ACTION : DATA will be transmitted, A bit received. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect stsa8 .base 0x1a8 01A8 01AB 01AE 8548DA 75D8C5 01E8 .sect ibase2 .base 0xe8 INITBASE2: S1DAT,STD ! load DATA in S1DAT S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA ajmp INITBASE2 mov mov
00E8 00EB 00ED 00EE 00F0
75D018 7948 09 D0D0 32
mov mov inc pop reti
psw,#SELRB3 r1, #STD r1 psw
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : B0, Arbitration lost in SLA and R/W as MST. Own SLA+R received, ACK returned. ! ACTION : DATA will be transmitted, A bit received. ! STA is set to restart MST mode after the bus is free again. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect stsb0 .base 0x1b0 01B0 01B3 01B6 8548DA 75D8E5 01E8 mov S1DAT,STD ! load DATA in S1DAT mov S1CON,#ENS1_STA_NOTSTO_NOTSI_AA_CR0 ajmp INITBASE2
2004 Apr 20
59
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
01B8 01BB 01BD
75D018 87DA 01F8
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : B8, DATA has been transmitted, ACK received. ! ACTION : DATA will be transmitted, ACK bit is received. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect stsb8 .base 0x1b8 mov psw,#SELRB3 mov S1DAT,@r1 ajmp SCON .sect .base scn 0xf8 mov S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA r1 psw
00F8 00FB 00FC 00FE
75D8C5 09 D0D0 32
SCON:
01C0 01C3 01C5
75D8C5 D0D0 32
inc pop reti !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : C0, DATA has been transmitted, NOT ACK received. ! ACTION : Enter not addressed SLV mode. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect stsc0 .base 0x1c0 mov S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA pop psw reti !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! STATE : C8, Last DATA has been transmitted (AA=0), ACK received. ! ACTION : Enter not addressed SLV mode. !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .sect stsc8 .base 0x1c8 mov S1CON,#ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0 ! clr SI, set AA pop psw reti
01C8 01CB 01CD
75D8C5 D0D0 32
!******************************************************************************************************** !******************************************************************************************************** ! END OF SI01 INTERRUPT ROUTINE !******************************************************************************************************** !********************************************************************************************************
2004 Apr 20
60
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Interrupt Priority Structure
The P8xC654X2 has an 8 source four-level interrupt structure (see Table 14). There are four SFRs associated with the four-level interrupt. They are IE, IEN1, IP, and IPH. The IPH (Interrupt Priority High) register makes the four-level interrupt structure possible. The IPH is located at SFR address B7H. The structure of the IPH register and a description of its bits is shown in Figure 38.
The function of the IPH SFR, when combined with the IP SFR, determines the priority of each interrupt. The priority of each interrupt is determined as shown in the following table: PRIORITY BITS IPH.x 0 0 1 1 IP.x 0 1 0 1 INTERRUPT PRIORITY LEVEL Level 0 (lowest priority) Level 1 Level 2 Level 3 (highest priority)
Table 14.
Interrupt Table
POLLING PRIORITY 1 2 3 4 5 6 7 REQUEST BITS IE0 - TP0 IE1 TF1 RI, TI TF2, EXF2 HARDWARE CLEAR? N (L)1 N Y N (L) Y (T) Y N N Y (T)2 VECTOR ADDRESS 03H 2BH 0BH 13H 1BH 23H 3BH X0
SOURCE
SI01 (I2C) T0 X1 T1 SP T2 NOTES: 1. L = Level activated 2. T = Transition activated
The priority scheme for servicing the interrupts is the same as that for the 80C51, except there are four interrupt levels rather than two as on the 80C51. An interrupt will be serviced as long as an interrupt of equal or higher priority is not already being serviced. If an interrupt of equal or higher level priority is being serviced, the new 7 IE (0A8H) EA 6 - 5 ET2 4 ES
interrupt will wait until it is finished before being serviced. If a lower priority level interrupt is being serviced, it will be stopped and the new interrupt serviced. When the new interrupt is finished, the lower priority level interrupt that was stopped will be completed. 3 ET1 2 EX1 1 ET0 0 EX0
Enable Bit = 1 enables the interrupt. Enable Bit = 0 disables it. BIT IE.7 IE.6 IE.5 IE.4 IE.3 IE.2 IE.1 IE.0 SYMBOL EA - ET2 ES ET1 EX1 ET0 EX0 FUNCTION Global disable bit. If EA = 0, all interrupts are disabled. If EA = 1, each interrupt can be individually enabled or disabled by setting or clearing its enable bit. - Timer 2 interrupt enable bit. Serial Port interrupt enable bit. Timer 1 interrupt enable bit. External interrupt 1 enable bit. Timer 0 interrupt enable bit. External interrupt 0 enable bit.
SU01745
Figure 36. IE Registers
2004 Apr 20
61
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
7 IP (0B8H) -
6 -
5 PT2
4 PS
3 PT1
2 PX1
1 PT0
0 PX0
Priority Bit = 1 assigns high priority Priority Bit = 0 assigns low priority BIT IP.7 IP.6 IP.5 IP.4 IP.3 IP.2 IP.1 IP.0 SYMBOL - - PT2 PS PT1 PX1 PT0 PX0 FUNCTION - - Timer 2 interrupt priority bit. Serial Port interrupt priority bit. Timer 1 interrupt priority bit. External interrupt 1 priority bit. Timer 0 interrupt priority bit. External interrupt 0 priority bit. Figure 37. IP Registers
SU01743
7 IPH (B7H) -
6 -
5 PT2H
4 PSH
3 PT1H
2 PX1H
1 PT0H
0 PX0H
Priority Bit = 1 assigns higher priority Priority Bit = 0 assigns lower priority BIT IPH.7 IPH.6 IPH.5 IPH.4 IPH.3 IPH.2 IPH.1 IPH.0 SYMBOL - - PT2H PSH PT1H PX1H PT0H PX0H FUNCTION - - Timer 2 interrupt priority bit high. Serial Port interrupt priority bit high. Timer 1 interrupt priority bit high. External interrupt 1 priority bit high. Timer 0 interrupt priority bit high. External interrupt 0 priority bit high. Figure 38. IPH Registers
SU01744
2004 Apr 20
62
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Reduced EMI Mode
The AO bit (AUXR.0) in the AUXR register when set disables the ALE output unless the CPU needs to perform an off-chip memory access.
The GPS bit is a general purpose user-defined flag. Note that bit 2 is not writable and is always read as a zero. This allows the DPS bit to be quickly toggled simply by executing an INC AUXR1 instruction without affecting the GPS bit.
Reduced EMI Mode
AUXR (8EH)
7 - 6 - 5 - 4 - 3 Fast/ STD I2C 2 - 1 - 0 AO DPS BIT0 AUXR1
DPTR1 DPTR0 DPH (83H) DPL (82H) EXTERNAL DATA MEMORY
AUXR.0
AO
Dual DPTR
The dual DPTR structure (see Figure 39) is a way by which the chip will specify the address of an external data memory location. There are two 16-bit DPTR registers that address the external memory, and a single bit called DPS = AUXR1/bit0 that allows the program code to switch between them. Figure 39.
SU00745A
* New Register Name: AUXR1# * SFR Address: A2H * Reset Value: xxxxxxx0B
AUXR1 (A2H)
7 - 6 - 5 - 4 LPEP
DPTR Instructions The instructions that refer to DPTR refer to the data pointer that is currently selected using the AUXR1/bit 0 register. The six instructions that use the DPTR are as follows: INC DPTR MOV DPTR, #data16 Increments the data pointer by 1 Loads the DPTR with a 16-bit constant Move code byte relative to DPTR to ACC Move external RAM (16-bit address) to ACC Move ACC to external RAM (16-bit address) Jump indirect relative to DPTR
3 GFS
2 0
1 -
0 DPS
MOV A, @ A+DPTR MOVX A, @ DPTR MOVX @ DPTR , A
Where: DPS = AUXR1/bit0 = Switches between DPTR0 and DPTR1. Select Reg DPTR0 DPTR1 DPS 0 1
JMP @ A + DPTR
The DPS bit status should be saved by software when switching between DPTR0 and DPTR1.
The data pointer can be accessed on a byte-by-byte basis by specifying the LOW or HIGH byte in an instruction which accesses the SFRs. See Application Note AN458 for more details.
FF
FF
FFFF
UPPER 128 BYTES INTERNAL RAM
SPECIAL FUNCTION REGISTER
EXTERNAL DATA MEMORY
80
80
LOWER 128 BYTES INTERNAL RAM
00
00
0000
SU01741
Figure 40. Internal and External Data Memory Address Space with EXTRAM = 0
2004 Apr 20
63
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
HARDWARE WATCHDOG TIMER (ONE-TIME ENABLED WITH RESET-OUT FOR P8XC654X2)
The WDT is intended as a recovery method in situations where the CPU may be subjected to software upset. The WDT consists of a 14-bit counter and the WatchDog Timer reset (WDTRST) SFR. The WDT is disabled at reset.
Using the WDT
To enable the WDT, the user must write 01EH and 0E1H in sequence to the WDTRST, SFR location 0A6H. When the WDT is enabled, the user needs to service it by writing 01EH and 0E1H to WDTRST to avoid a WDT overflow. The 14-bit counter overflows when it reaches 16383 (3FFFH) and this will reset the device. When the WDT is enabled, it will increment every machine cycle while the oscillator is running. This means the user must reset the WDT at least every 16383 machine cycles. To reset the WDT, the user must write 01EH and 0E1H to WDTRST. WDTRST is a write only register. The WDT counter cannot be read or written. When the WDT overflows, it will generate an output RESET pulse at the reset pin (see note below). The RESET pulse duration is 98 x Tosc (6-clock mode; 196 in 12-clock mode), where Tosc = 1/fosc. To make the best use of the WDT, it should be serviced in those sections of code that will periodically be executed within the time required to prevent a WDT reset.
2004 Apr 20
64
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
ABSOLUTE MAXIMUM RATINGS1, 2, 3
PARAMETER Operating temperature under bias Storage temperature range Voltage on EA/VPP pin to VSS Voltage on any other pin to VSS Maximum IOL per I/O pin
4
RATING 0 to +70 or -40 to +85 -65 to +150 0 to +13.0 -0.5 to +6.0 15
UNIT C C V V mA
Power dissipation (based on package heat transfer limitations, not device power consumption) 1.5 W NOTES: 1. Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any conditions other than those described in the AC and DC Electrical Characteristics section of this specification is not implied. 2. This product includes circuitry specifically designed for the protection of its internal devices from the damaging effects of excessive static charge. Nonetheless, it is suggested that conventional precautions be taken to avoid applying greater than the rated maximum. 3. Parameters are valid over operating temperature range unless otherwise specified. All voltages are with respect to VSS unless otherwise noted. 4. Transient voltage only.
AC ELECTRICAL CHARACTERISTICS
Tamb = 0C to +70C or -40C to +85C CLOCK FREQUENCY RANGE SYMBOL 1/tCLCL FIGURE 46 PARAMETER Oscillator frequency OPERATING MODE 6-clock 6-clock 12-clock 12-clock POWER SUPPLY VOLTAGE 5 V "10 % 2.7 V to 5.5 V 5 V "10 % 2.7 V to 5.5 V MIN 0 0 0 0 MAX 30 16 33 16 UNIT MHz MHz MHz MHz
2004 Apr 20
65
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
DC ELECTRICAL CHARACTERISTICS
Tamb = 0 C to +70 C or -40 C to +85 C; VCC = 2.7 V to 5.5 V; VSS = 0 V (16 MHz max. CPU clock) SYMBOL PARAMETER TEST CONDITIONS except P1.6 and P1.7 4.0 V < VCC < 5.5 V 2.7 V < VCC < 4.0 V VIL1 VIL2 VIH VIH1 VOL VOL1 VOL2 VOH VOH1 IIL ITL ILI ICC Input LOW voltage to EA Input LOW voltage to P1.6/SCL, P1.7/SDA5 Input HIGH voltage (ports 0, 1, 2, 3, EA) Input HIGH voltage, XTAL1, RST11 Output LOW voltage, ports 1, and P1.7 28, except P1.6 VCC = 2.7 V; IOL = 1.6 mA2 LIMITS MIN VIL Input LOW voltage11, -0.5 -0.5 -0.5 -0.5 0.2VCC + 0.9 0.7VCC - - - VCC - 0.7 VCC - 0.7 VCC - 0.7 -1 - - TYP1 MAX 0.2VCC - 0.1 0.7VCC 0.2VDD - 0.3 0.3VDD VCC + 0.5 VCC + 0.5 0.4 0.4 0.4 - - - -50 -650 10 V V V V V V V V V V V V mA mA mA UNIT
Output LOW voltage, port 0, ALE, PSEN8, 7 Output LOW voltage, P1.6/SCL, P1.7/SDA Output HIGH voltage, ports 1, 2, 3 3
VCC = 2.7 V; IOL = 3.2 mA2
I OL
= 3.0 mA7
VCC = 2.7 V; IOH = -20 mA VCC = 4.5 V; IOH = -30 mA
Output HIGH voltage (port 0 in external bus VCC = 2.7 V; IOH = -3.2 mA mode), ALE9, PSEN3 Logical 0 input current, ports 1, 2, 3 Logical 1-to-0 transition current, ports 1, 2, 36 Input leakage current, port 0 Power supply current (see Figure 49 and Source Code): Active mode @ 16 MHz Idle mode @ 16 MHz Power-down mode or clock stopped (see Figure 45 for conditions) 12 Tamb = 0 C to 70 C Tamb = -40 C to +85 C VIN = 0.4 V VIN = 2.0 V; See note 4 0.45 < VIN < VCC - 0.3
mA mA 2 3 1.2 40 - 225 15 30 50 mA mA V k pF
VRAM RRST CIO
RAM keep-alive voltage Internal reset pull-down resistor Pin capacitance10 (except EA)
NOTES: 1. Typical ratings are not guaranteed. Values listed are based on tests conducted on limited number of samples at room temperature. 2. Capacitive loading on ports 0 and 2 may cause spurious noise to be superimposed on the VOLs of ALE and ports 1 and 3. The noise is due to external bus capacitance discharging into the port 0 and port 2 pins when these pins make 1-to-0 transitions during bus operations. In the worst cases (capacitive loading > 100 pF), the noise pulse on the ALE pin may exceed 0.8 V. In such cases, it may be desirable to qualify ALE with a Schmitt Trigger, or use an address latch with a Schmitt Trigger STROBE input. IOL can exceed these conditions provided that no single output sinks more than 5 mA and no more than two outputs exceed the test conditions. 3. Capacitive loading on ports 0 and 2 may cause the VOH on ALE and PSEN to momentarily fall below the VCC-0.7 specification when the address bits are stabilizing. 4. Pins of ports 1, 2 and 3 source a transition current when they are being externally driven from 1 to 0. The transition current reaches its maximum value when VIN is approximately 2 V. 5. See Figures 51 through 54 for ICC test conditions and Figure 49 for ICC vs. Frequency 12-clock mode characteristics: Active mode (operating): ICC = 1.0 mA + 1.1 mA x FREQ.[MHz] Active mode (reset): ICC = 7.0 mA + 0.6 mA FREQ.[MHz] Idle mode: ICC = 1.0 mA + 0.22 mA FREQ.[MHz] 6. This value applies to Tamb = 0 C to +70 C. For Tamb = -40 C to +85 C, ITL = -750 mA. 7. Load capacitance for port 0, ALE, and PSEN = 100 pF, load capacitance for all other outputs = 80 pF. 8. Under steady state (non-transient) conditions, IOL must be externally limited as follows: 15 mA (*NOTE: This is 85 C specification.) Maximum IOL per port pin: 26 mA Maximum IOL per 8-bit port: Maximum total IOL for all outputs: 71 mA If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test conditions. 9. ALE is tested to VOH1, except when ALE is off then VOH is the voltage specification. 10. Pin capacitance is characterized but not tested. Pin capacitance is less than 25 pF. Pin capacitance of ceramic package is less than 15 pF (except EA is 25 pF).
2004 Apr 20
66
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
11. To improve noise rejection a nominal 100 ns glitch rejection circuitry has been added to the RST pin, and a nominal 15 ns glitch rejection circuitry has been added to the INT0 and INT1 pins. Previous devices provided only an inherent 5 ns of glitch rejection. 12. Power-down mode for 3 V range: Commercial Temperature Range - typ: 0.5 mA, max. 20 mA; Industrial Temperature Range - typ. 1.0 mA, max. 30 mA;
2004 Apr 20
67
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
DC ELECTRICAL CHARACTERISTICS
Tamb = 0 C to +70 C or -40 C to +85 C; VCC = 5 V 10 %; VSS = 0 V (30/33 MHz max. CPU clock) SYMBOL PARAMETER TEST CONDITIONS 4.5 V < VCC < 5.5 V RST11 VCC = 4.5 V; IOL = 1.6 mA2 VCC = 4.5 V; IOL = 3.2 mA2 VCC = 4.5 V; IOH = -30 mA VCC = 4.5 V; IOH = -3.2 mA VIN = 0.4 V VIN = 2.0 V; See note 4 0.45 < VIN < VCC - 0.3 LIMITS MIN VIL VIH VIH1 VOL VOL1 VOH VOH1 IIL ITL ILI ICC Input LOW voltage11 Input HIGH voltage (ports 0, 1, 2, 3, EA) Input HIGH voltage, XTAL1, Output LOW voltage, ports 1, 2, 3 8 Output LOW voltage, port 0, ALE, PSEN 7, 8 Output HIGH voltage, ports 1, 2, 3 3 Output HIGH voltage (port 0 in external bus mode), ALE9, PSEN3 Logical 0 input current, ports 1, 2, 3 Logical 1-to-0 transition current, ports 1, 2, 36 Input leakage current, port 0 Power supply current Active mode (see Note 5) Idle mode (see Note 5) Power-down mode or clock stopped (see Figure 54 for conditions) VRAM RRST CIO RAM keep-alive voltage Internal reset pull-down resistor Pin capacitance10 (except EA) Tamb = 0 C to 70 C Tamb = -40 C to +85 C 1.2 40 - 225 15 2 3 30 50 mA mA V k pF -0.5 0.2VCC + 0.9 0.7VCC - - VCC - 0.7 VCC - 0.7 -1 - - TYP1 MAX 0.2VCC - 0.1 VCC + 0.5 VCC + 0.5 0.4 0.4 - - -50 -650 10 V V V V V V V mA mA mA UNIT
NOTES: 1. Typical ratings are not guaranteed. The values listed are at room temperature, 5 V. 2. Capacitive loading on ports 0 and 2 may cause spurious noise to be superimposed on the VOLs of ALE and ports 1 and 3. The noise is due to external bus capacitance discharging into the port 0 and port 2 pins when these pins make 1-to-0 transitions during bus operations. In the worst cases (capacitive loading > 100 pF), the noise pulse on the ALE pin may exceed 0.8 V. In such cases, it may be desirable to qualify ALE with a Schmitt Trigger, or use an address latch with a Schmitt Trigger STROBE input. IOL can exceed these conditions provided that no single output sinks more than 5 mA and no more than two outputs exceed the test conditions. 3. Capacitive loading on ports 0 and 2 may cause the VOH on ALE and PSEN to momentarily fall below the VCC-0.7 specification when the address bits are stabilizing. 4. Pins of ports 1, 2 and 3 source a transition current when they are being externally driven from 1 to 0. The transition current reaches its maximum value when VIN is approximately 2 V. 5. See Figures 51 through 54 for ICC test conditions and Figure 49 for ICC vs. Frequency. 12-clock mode characteristics: Active mode (operating): ICC = 1.0 mA + 1.1 mA x FREQ.[MHz] Active mode (reset): ICC = 7.0 mA + 0.6 mA FREQ.[MHz] Idle mode: ICC = 1.0 mA + 0.22 mA FREQ.[MHz] 6. This value applies to Tamb = 0C to +70C. For Tamb = -40C to +85C, ITL = -750 . 7. Load capacitance for port 0, ALE, and PSEN = 100 pF, load capacitance for all other outputs = 80 pF. 8. Under steady state (non-transient) conditions, IOL must be externally limited as follows: Maximum IOL per port pin: 15 mA (*NOTE: This is 85 C specification.) 26 mA Maximum IOL per 8-bit port: Maximum total IOL for all outputs: 71 mA If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test conditions. 9. ALE is tested to VOH1, except when ALE is off then VOH is the voltage specification. 10. Pin capacitance is characterized but not tested. Pin capacitance is less than 25 pF. Pin capacitance of ceramic package is less than 15 pF (except EA is 25 pF). 11. To improve noise rejection a nominal 100 ns glitch rejection circuitry has been added to the RST pin, and a nominal 15 ns glitch rejection circuitry has been added to the INT0 and INT1 pins. Previous devices provided only an inherent 5 ns of glitch rejection.
2004 Apr 20
68
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
AC ELECTRICAL CHARACTERISTICS (12-CLOCK MODE, 5 V 10 % OPERATION)
Tamb = 0 C to +70 C or -40 C to +85 C ; VCC = 5 V 10 %, VSS = 0 V1,2,3,4 Symbol Figure Parameter Limits MIN 1/tCLCL tLHLL tAVLL tLLAX tLLIV tLLPL tPLPH tPLIV tPXIX tPXIZ tAVIV tPLAZ tRLRH tWLWH tRLDV tRHDX tRHDZ tLLDV tAVDV tLLWL tAVWL tQVWX tWHQX tQVWH tRLAZ tWHLH tCHCX tCLCX tCLCH tCHCL tXLXL tQVXH tXHQX tXHDX tXHDV 46 41 41 41 41 41 41 41 41 41 41 41 42 43 42 42 42 42 42 42, 43 42, 43 43 43 43 42 42, 43 46 46 46 46 45 45 45 45 45 Oscillator frequency ALE pulse width Address valid to ALE LOW Address hold after ALE LOW ALE LOW to valid instruction in ALE LOW to PSEN LOW PSEN pulse width PSEN LOW to valid instruction in Input instruction hold after PSEN Input instruction float after PSEN Address to valid instruction in PSEN LOW to address float RD pulse width WR pulse width RD LOW to valid data in Data hold after RD Data float after RD ALE LOW to valid data in Address to valid data in ALE LOW to RD or WR LOW Address valid to WR LOW or RD LOW Data valid to WR transition Data hold after WR Data valid to WR HIGH RD LOW to address float RD or WR HIGH to ALE HIGH High time Low time Rise time Fall time Serial port clock cycle time Output data setup to clock rising edge Output data hold after clock rising edge Input data hold after clock rising edge Clock rising edge to input data valid5 0 2tCLCL - 8 tCLCL - 13 tCLCL - 20 - tCLCL - 10 3tCLCL - 10 - 0 - - - 6tCLCL - 20 6tCLCL - 20 - 0 - - - 3tCLCL - 15 4tCLCL -15 tCLCL - 25 tCLCL - 15 7tCLCL - 5 - tCLCL - 10 0.32tCLCL 0.32tCLCL - - 12tCLCL 10tCLCL - 25 2tCLCL - 15 0 - 16 MHz Clock MAX 33 - - - 4tCLCL - 35 - - 3tCLCL - 35 - tCLCL - 10 5tCLCL - 35 10 - - 5tCLCL - 35 - 2tCLCL - 10 8tCLCL - 35 9tCLCL - 35 3tCLCL + 15 - - - - 0 tCLCL + 10 tCLCL - tCLCX tCLCL - tCHCX 5 5 - - - - 10tCLCL - 133 MIN - 117 49.5 42.5 - 52.5 177.5 - 0 - - - 355 355 - 0 - - - 172.5 235 37.5 47.5 432.5 - 52.5 - - - - 750 600 110 0 - MAX - - - - 215 - - 152.5 - 52.5 277.5 10 - - 277.5 - 115 465 527.5 202.5 - - - - 0 72.5 - - - - - - - - 492 MHz ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Unit
Data Memory
External Clock
Shift register
NOTES: 1. Parameters are valid over operating temperature range unless otherwise specified. 2. Load capacitance for port 0, ALE, and PSEN = 100 pF, load capacitance for all outputs = 80 pF 3. Interfacing the microcontroller to devices with float time up to 45 ns is permitted. This limited bus contention will not cause damage to port 0 drivers. 4. Parts are guaranteed by design to operate down to 0 Hz. 5. Below 16 MHz this parameter is 8tCLCL - 133.
2004 Apr 20
69
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
AC ELECTRICAL CHARACTERISTICS (12-CLOCK MODE, 2.7 V TO 5.5 V OPERATION)
Tamb = 0 C to +70 C or -40 C to +85 C ; VCC = 2.7 V to 5.5 V, VSS = 0 V1,2,3,4 Symbol Figure Parameter Limits MIN 1/tCLCL tLHLL tAVLL tLLAX tLLIV tLLPL tPLPH tPLIV tPXIX tPXIZ tAVIV tPLAZ tRLRH tWLWH tRLDV tRHDX tRHDZ tLLDV tAVDV tLLWL tAVWL tQVWX tWHQX tQVWH tRLAZ tWHLH tCHCX tCLCX tCLCH tCHCL tXLXL tQVXH tXHQX tXHDX tXHDV 46 41 41 41 41 41 41 41 41 41 41 41 42 43 42 42 42 42 42 42, 43 42, 43 43 43 43 42 42, 43 46 46 46 46 45 45 45 45 45 Oscillator frequency ALE pulse width Address valid to ALE LOW Address hold after ALE LOW ALE LOW to valid instruction in ALE LOW to PSEN LOW PSEN pulse width PSEN LOW to valid instruction in Input instruction hold after PSEN Input instruction float after PSEN Address to valid instruction in PSEN LOW to address float RD pulse width WR pulse width RD LOW to valid data in Data hold after RD Data float after RD ALE LOW to valid data in Address to valid data in ALE LOW to RD or WR LOW Address valid to WR LOW or RD LOW Data valid to WR transition Data hold after WR Data valid to WR HIGH RD LOW to address float RD or WR HIGH to ALE HIGH High time Low time Rise time Fall time Serial port clock cycle time Output data setup to clock rising edge Output data hold after clock rising edge Input data hold after clock rising edge Clock rising edge to input data valid5 0 2tCLCL - 10 tCLCL - 15 tCLCL - 25 - tCLCL - 15 3tCLCL - 15 - 0 - - - 6tCLCL - 25 6tCLCL - 25 - 0 - - - 3tCLCL - 20 4tCLCL - 20 tCLCL - 30 tCLCL - 20 7tCLCL - 10 - tCLCL - 15 0.32tCLCL 0.32tCLCL - - 12tCLCL 10tCLCL - 25 2tCLCL - 15 0 - MAX 16 - - - 4tCLCL - 55 - - 3tCLCL - 55 - tCLCL - 10 5tCLCL - 50 10 - - 5tCLCL - 50 - 2tCLCL -20 8tCLCL - 55 9tCLCL - 50 3tCLCL +20 - - - - 0 tCLCL +15 tCLCL - tCLCX tCLCL - tCHCX 5 5 - - - - 10tCLCL - 133 16 MHz Clock MIN - 115 47.5 37.5 - 47.5 172.5 - 0 - - - 350 350 - 0 - - - 167.5 230 32.5 42.5 427.5 - 47.5 - - - - 750 600 110 0 - MAX - - - - 195 - - 132.5 - 52.5 262.5 10 - - 262.5 - 105 445 512.5 207.5 - - - - 0 77.5 - - - - - - - - 492 MHz ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Unit
Data Memory
External Clock
Shift register
NOTES: 1. Parameters are valid over operating temperature range unless otherwise specified. 2. Load capacitance for port 0, ALE, and PSEN = 100 pF, load capacitance for all outputs = 80 pF 3. Interfacing the microcontroller to devices with float time up to 45 ns is permitted. This limited bus contention will not cause damage to port 0 drivers. 4. Parts are guaranteed by design to operate down to 0 Hz. 5. Below 16 MHz this parameter is 8tCLCL - 133.
2004 Apr 20
70
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
AC ELECTRICAL CHARACTERISTICS (6-CLOCK MODE, 5 V 10 % OPERATION)
Tamb = 0 C to +70 C or -40 C to +85 C; VCC = 5 V 10 %, VSS = 0 V1,2,3,4,5 Symbol Figure Parameter Limits MIN 1/tCLCL tLHLL tAVLL tLLAX tLLIV tLLPL tPLPH tPLIV tPXIX tPXIZ tAVIV 46 41 41 41 41 41 41 41 41 41 41 Oscillator frequency ALE pulse width Address valid to ALE LOW Address hold after ALE LOW ALE LOW to valid instruction in ALE LOW to PSEN LOW PSEN pulse width PSEN LOW to valid instruction in Input instruction hold after PSEN Input instruction float after PSEN Address to valid instruction in PSEN LOW to address float RD pulse width WR pulse width RD LOW to valid data in Data hold after RD Data float after RD ALE LOW to valid data in Address to valid data in ALE LOW to RD or WR LOW Address valid to WR LOW or RD LOW Data valid to WR transition Data hold after WR Data valid to WR HIGH RD LOW to address float RD or WR HIGH to ALE HIGH High time Low time Rise time Fall time Serial port clock cycle time Output data setup to clock rising edge Output data hold after clock rising edge Input data hold after clock rising edge Clock rising edge to input data valid6 0 tCLCL - 8 0.5tCLCL - 13 0.5tCLCL - 20 - 0.5tCLCL - 10 1.5tCLCL - 10 - 0 - - - 3tCLCL - 20 3tCLCL - 20 - 0 - - - 1.5tCLCL - 15 2tCLCL -15 0.5tCLCL - 25 0.5tCLCL - 15 3.5tCLCL - 5 - 0.5tCLCL - 10 0.4tCLCL 0.4tCLCL - - 6tCLCL 5tCLCL -25 tCLCL - 15 0 - 16 MHz Clock MAX 30 - - - 2tCLCL -35 - - 1.5tCLCL - 35 - 0.5tCLCL - 10 2.5tCLCL - 35 10 - - 2.5tCLCL - 35 - tCLCL -10 4tCLCL - 35 4.5tCLCL - 35 1.5tCLCL +15 - - - - 0 0.5tCLCL +10 tCLCL - tCLCX tCLCL - tCHCX 5 5 - - - - 5tCLCL - 133 MIN - 54.5 18.25 11.25 - 21.25 83.75 - 0 - - - 167.5 167.5 - 0 - - - 78.75 110 6.25 16.25 213.75 - 21.25 - - - - 375 287.5 47.5 0 - MAX - - - - 90 - - 58.75 - 21.25 121.25 10 - - 121.25 - 52.5 215 246.25 108.75 - - - - 0 41.25 - - - - - - - - 179.5 MHz ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Unit
tPLAZ 41 Data Memory tRLRH tWLWH tRLDV tRHDX tRHDZ tLLDV tAVDV tLLWL tAVWL tQVWX tWHQX tQVWH tRLAZ 42 43 42 42 42 42 42 42, 43 42, 43 43 43 43 42
tWHLH 42, 43 External Clock tCHCX tCLCX tCLCH 46 46 46
tCHCL 46 Shift register tXLXL tQVXH tXHQX tXHDX tXHDV 45 45 45 45 45
NOTES: 1. Parameters are valid over operating temperature range unless otherwise specified. 2. Load capacitance for port 0, ALE, and PSEN=100 pF, load capacitance for all outputs = 80 pF 3. Interfacing the microcontroller to devices with float time up to 45ns is permitted. This limited bus contention will not cause damage to port 0 drivers. 4. Parts are guaranteed by design to operate down to 0 Hz. 5. Data shown in the table are the best mathematical models for the set of measured values obtained in tests. If a particular parameter calculated at a customer specified frequency has a negative value, it should be considered equal to zero. 6. Below 16 MHz this parameter is 4tCLCL - 133
2004 Apr 20
71
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
AC ELECTRICAL CHARACTERISTICS (6-CLOCK MODE, 2.7 V TO 5.5 V OPERATION)
Tamb = 0 C to +70 C or -40 C to +85 C; VCC=2.7 V to 5.5 V, VSS = 0 V1,2,3,4,5 Symbol Figure Parameter Limits MIN 1/tCLCL tLHLL tAVLL tLLAX tLLIV tLLPL tPLPH tPLIV tPXIX tPXIZ tAVIV 46 41 41 41 41 41 41 41 41 41 41 Oscillator frequency ALE pulse width Address valid to ALE LOW Address hold after ALE LOW ALE LOW to valid instruction in ALE LOW to PSEN LOW PSEN pulse width PSEN LOW to valid instruction in Input instruction hold after PSEN Input instruction float after PSEN Address to valid instruction in PSEN LOW to address float RD pulse width WR pulse width RD LOW to valid data in Data hold after RD Data float after RD ALE LOW to valid data in Address to valid data in ALE LOW to RD or WR LOW Address valid to WR LOW or RD LOW Data valid to WR transition Data hold after WR Data valid to WR HIGH RD LOW to address float RD or WR HIGH to ALE HIGH High time Low time Rise time Fall time Serial port clock cycle time Output data setup to clock rising edge Output data hold after clock rising edge Input data hold after clock rising edge 0 tCLCL - 10 0.5tCLCL - 15 0.5tCLCL - 25 - 0.5tCLCL - 15 1.5tCLCL - 15 - 0 - - - 3tCLCL - 25 3tCLCL - 25 - 0 - - - 1.5tCLCL - 20 2tCLCL - 20 0.5tCLCL - 30 0.5tCLCL - 20 3.5tCLCL - 10 - 0.5tCLCL - 15 0.4tCLCL 0.4tCLCL - - 6tCLCL 5tCLCL -25 tCLCL - 15 0 - 0 4.7 4.0 4.7 4.0 4.7 MAX 16 - - - 2tCLCL -55 - - 1.5tCLCL - 55 - 0.5tCLCL - 10 2.5tCLCL - 50 10 - - 2.5tCLCL - 50 - tCLCL - 20 4tCLCL - 55 4.5tCLCL - 50 1.5tCLCL + 20 - - - - 0 0.5tCLCL + 15 tCLCL - tCLCX tCLCL - tCHCX 5 5 - - - - 5tCLCL - 133 100 - - - - - 16 MHz Clock MIN - 52.5 16.25 6.25 - 16.25 78.75 - 0 - - - 162.5 162.5 - 0 - - - 73.75 105 1.25 11.25 208.75 - 16.25 - - - - 375 287.5 47.5 0 - 0 1.3 0.6 1.3 0.6 0.6 MAX - - - - 70 - - 38.75 - 21.25 101.25 10 - - 106.25 - 42.5 195 231.25 113.75 - - - - 0 46.25 - - - - - - - - 179.5 400 - - - - - MHz ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns kHz s s s s s Unit
tPLAZ 41 Data Memory tRLRH tWLWH tRLDV tRHDX tRHDZ tLLDV tAVDV tLLWL tAVWL tQVWX tWHQX tQVWH tRLAZ 42 43 42 42 42 42 42 42, 43 42, 43 43 43 43 42
tWHLH 42, 43 External Clock tCHCX tCLCX tCLCH 46 46 46
tCHCL 46 Shift register tXLXL tQVXH tXHQX tXHDX 45 45 45 45
tXHDV 45 Clock rising edge to input data valid6 2C interface timing I fSCL tBUF tHD; STA tLOW tHIGH tSU; STA 2004 Apr 20 SCL clock frequency Bus free time between a STOP and START condition Hold time (repeated) START condition. After this period, the first clock pulse is generated LOW period of the SCL clock High period of the SCL clock Set-up time for a repeated START condition
72
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
tHD;DAT
Data hold time: - for CBUS compatible masters - for I2C-bus devices Data set-up time Rise time of both SDA and SCL signals Fall time of both SDA and SCL signals Set-up time for STOP condition Capacitive load for each bus line Pulse width of spikes which must be suppressed by the input filter
s 5.0 0 250 - - 4.0 - - - - - 1000 300 - 400 - - 0 100 20 + 0.1 cb 20 + 0.1 cb 0.6 - 0 - 0.9 - 300 300 - 400 50 ns ns ns s pF ns
tSU;DAT tFD, tFC tFD, tFC tSU; STO Cb tSP
NOTES: 1. Parameters are valid over operating temperature range unless otherwise specified. 2. Load capacitance for port 0, ALE, and PSEN=100 pF, load capacitance for all outputs = 80 pF 3. Interfacing the microcontroller to devices with float time up to 45ns is permitted. This limited bus contention will not cause damage to port 0 drivers. 4. Parts are guaranteed by design to operate down to 0 Hz. 5. Data shown in the table are the best mathematical models for the set of measured values obtained in tests. If a particular parameter calculated at a customer specified frequency has a negative value, it should be considered equal to zero. 6. Below 16 MHz this parameter is 4tCLCL - 133
2004 Apr 20
73
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
EXPLANATION OF THE AC SYMBOLS
Each timing symbol has five characters. The first character is always `t' (= time). The other characters, depending on their positions, indicate the name of a signal or the logical status of that signal. The designations are: A - Address C - Clock D - Input data H - Logic level HIGH I - Instruction (program memory contents) L - Logic level LOW, or ALE P - PSEN Q - Output data R - RD signal t - Time V - Valid W - WR signal X - No longer a valid logic level Z - Float Examples: tAVLL = Time for address valid to ALE LOW. tLLPL =Time for ALE LOW to PSEN LOW.
tLHLL
ALE
tAVLL
tLLPL
PSEN
tPLPH tLLIV tPLIV tPLAZ tPXIX
INSTR IN
tLLAX
tPXIZ
PORT 0
A0-A7
A0-A7
tAVIV
PORT 2 A0-A15 A8-A15
SU00006
Figure 41. External Program Memory Read Cycle
ALE
tWHLH
PSEN
tLLDV tLLWL
RD
tRLRH
tAVLL
PORT 0
tLLAX tRLAZ
A0-A7 FROM RI OR DPL
tRLDV tRHDX
DATA IN
tRHDZ
A0-A7 FROM PCL
INSTR IN
tAVWL tAVDV
PORT 2 P2.0-P2.7 OR A8-A15 FROM DPF A0-A15 FROM PCH
SU00025
Figure 42. External Data Memory Read Cycle
2004 Apr 20
74
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
ALE
tWHLH
PSEN
tLLWL
WR
tWLWH
tAVLL
PORT 0
tLLAX
tQVWX tQVWH
tWHQX
A0-A7 FROM RI OR DPL
DATA OUT
A0-A7 FROM PCL
INSTR IN
tAVWL
PORT 2
P2.0-P2.7 OR A8-A15 FROM DPF
A0-A15 FROM PCH
SU00026
Figure 43. External Data Memory Write Cycle
repeated START condition START or repeated START condition tRD SDA (INPUT/OUTPUT) tBUF tFD SCL (INPUT/OUTPUT) tRC tFC
t SP
tSU;STA STOP condition
START condition
0.7 VDD 0.3 VDD
tSU; STO 0.7 VDD 0.3 VDD tSU;DAT3
tHD;STA
tLOW
tHIGH
tSU;DAT1
tHD;DAT
tSU;DAT2
SU01742
Figure 44. Timing I2C interface
2004 Apr 20
75
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
INSTRUCTION ALE
0
1
2
3
4
5
6
7
8
tXLXL
CLOCK
tQVXH
OUTPUT DATA 0 WRITE TO SBUF
tXHQX
1 2 3 4 5 6 7
tXHDV
INPUT DATA VALID CLEAR RI VALID
tXHDX
SET TI VALID VALID VALID VALID VALID VALID
SET RI
SU00027
Figure 45. Shift Register Mode Timing
VCC-0.5 0.45V
0.7VCC 0.2VCC-0.1
tCHCL
tCLCX tCLCL
tCHCX tCLCH
SU00009
Figure 46. External Clock Drive
VCC-0.5
0.2VCC+0.9 VLOAD 0.2VCC-0.1
VLOAD+0.1V VLOAD-0.1V
TIMING REFERENCE POINTS
VOH-0.1V VOL+0.1V
0.45V
NOTE: AC inputs during testing are driven at VCC -0.5 for a logic `1' and 0.45V for a logic `0'. Timing measurements are made at VIH min for a logic `1' and VIL max for a logic `0'.
NOTE: For timing purposes, a port is no longer floating when a 100mV change from load voltage occurs, and begins to float when a 100mV change from the loaded VOH/VOL level occurs. IOH/IOL 20mA.
SU00717
SU00718
Figure 47. AC Testing Input/Output
Figure 48. Float Waveform
2004 Apr 20
76
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
40
35 MAX ACTIVE MODE FREQ. + 1.0 ICCMAX = 1.1 30
ICC(mA)
25
20
15
TYP ACTIVE MODE MAX IDLE MODE ICCMAX = 0.22 FREQ. + 1.0
10
5
TYP IDLE MODE
4
8
12
16
20
24
28
32
36
FREQ AT XTAL1 (MHz)
SU01684
Figure 49. ICC vs. FREQ for 12-clock operation Valid only within frequency specifications of the specified operating voltage
/* ## as31 version V2.10 / *js* / ## ## ## source file: idd_ljmp1.asm ## list file: idd_ljmp1.lst created Fri Apr 20 15:51:40 2001 ## ########################################################## #0000 # AUXR equ 08Eh #0000 # CKCON equ 08Fh # # #0000 # org 0 # # LJMP_LABEL: 0000 /75;/8E;/01; # MOV AUXR,#001h ; turn off ALE 0003 /02;/FF;/FD; # LJMP LJMP_LABEL ; jump to end of address space 0005 /00; # NOP # #FFFD # org 0fffdh # # LJMP_LABEL: # FFFD /02;/FD;FF; # LJMP LJMP_LABEL #; NOP # # */" Figure 50. Source code used in measuring IDD operational
SU01499
2004 Apr 20
77
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
VCC ICC VCC VCC P0 EA (NC) CLOCK SIGNAL XTAL2 XTAL1 VSS (NC) CLOCK SIGNAL XTAL2 XTAL1 VSS VCC RST P0 EA VCC
VCC ICC
VCC
RST
SU00719
SU00720
Figure 51. ICC Test Condition, Active Mode All other pins are disconnected
Figure 52. ICC Test Condition, Idle Mode All other pins are disconnected
VCC-0.5 0.45V
0.7VCC 0.2VCC-0.1
tCHCL
tCLCX tCLCL
tCHCX tCLCH
SU00009
Figure 53. Clock Signal Waveform for ICC Tests in Active and Idle Modes tCLCH = tCHCL = 5ns
VCC ICC VCC RST P0 EA (NC) XTAL2 XTAL1 VSS VCC
SU00016
Figure 54. ICC Test Condition, Power-down mode All other pins are disconnected. VCC = 2 V to 5.5 V
2004 Apr 20
78
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
EPROM CHARACTERISTICS
The 87C654X2 can be programmed by using a modified Improved Quick-Pulse ProgrammingTM algorithm. It differs from older methods in the value used for VPP (programming supply voltage) and in the width and number of the ALE/PROG pulses. The family contains two signature bytes that can be read and used by an EPROM programming system to identify the device. The signature bytes identify the device as being manufactured by Philips. Table 15 shows the logic levels for reading the signature byte, and for programming the program memory, the encryption table, and the security bits. The circuit configuration and waveforms for quick-pulse programming are shown in Figures 55 and 56. Figure 57 shows the circuit configuration for normal program memory verification.
device. The VPP source should be well regulated and free of glitches and overshoot. Program Verification If security bits 2 and 3 have not been programmed, the on-chip program memory can be read out for program verification. The address of the program memory locations to be read is applied to ports 1 and 2 as shown in Figure 57. The other pins are held at the `Verify Code Data' levels indicated in Table 15. The contents of the address location will be emitted on port 0. External pull-ups are required on port 0 for this operation. If the 64 byte encryption table has been programmed, the data presented at port 0 will be the exclusive NOR of the program byte with one of the encryption bytes. The user will have to know the encryption table contents in order to correctly decode the verification data. The encryption table itself cannot be read out. Reading the Signature Bytes The signature bytes are read by the same procedure as a normal verification of locations 030H and 031H, except that P3.6 and P3.7 need to be pulled to a logic LOW. The values are: (030H) = 15H indicates manufactured by Philips (031H) = 99H (060H) = 02H
Quick-Pulse Programming
The setup for microcontroller quick-pulse programming is shown in Figure 55. Note that the device is running with a 4 to 6MHz oscillator. The reason the oscillator needs to be running is that the device is executing internal address and program data transfers. The address of the EPROM location to be programmed is applied to ports 1 and 2, as shown in Figure 55. The code byte to be programmed into that location is applied to port 0. RST, PSEN and pins of ports 2 and 3 specified in Table 15 are held at the `Program Code Data' levels indicated in Table 15. The ALE/PROG is pulsed LOW 5 times as shown in Figure 56. To program the encryption table, repeat the 5 pulse programming sequence for addresses 0 through 1FH, using the `Pgm Encryption Table' levels. Do not forget that after the encryption table is programmed, verification cycles will produce only encrypted data. To program the security bits, repeat the 5 pulse programming sequence using the `Pgm Security Bit' levels. After one security bit is programmed, further programming of the code memory and encryption table is disabled. However, the other security bits can still be programmed. Note that the EA/VPP pin must not be allowed to go above the maximum specified VPP level for any amount of time. Even a narrow glitch above that voltage can cause permanent damage to the
Program/Verify Algorithms
Any algorithm in agreement with the conditions listed in Table 15, and which satisfies the timing specifications, is suitable.
Security Bits
With none of the security bits programmed the code in the program memory can be verified. If the encryption table is programmed, the code will be encrypted when verified. When only security bit 1 (see Table 16) is programmed, MOVC instructions executed from external program memory are disabled from fetching code bytes from the internal memory, EA is latched on Reset and all further programming of the EPROM is disabled. When security bits 1 and 2 are programmed, in addition to the above, verify mode is disabled. When all three security bits are programmed, all of the conditions above apply and all external program memory execution is disabled.
Encryption Array
64 bytes of encryption array are initially unprogrammed (all 1s).
TMTrademark phrase of Intel Corporation. 2004 Apr 20 79
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Table 15. EPROM Programming Modes
MODE Read signature Program code data Verify code data Pgm encryption table Pgm security bit 1 Pgm security bit 2 Pgm security bit 3 Program to 6-clock mode Verify 6-clock4 Verify security bits5 RST 1 1 1 1 1 1 1 1 1 1 PSEN 0 0 0 0 0 0 0 0 0 0 ALE/PROG 1 0* 1 0* 0* 0* 0* 0* 1 1 EA/VPP 1 VPP 1 VPP VPP VPP VPP VPP 1 1 P2.7 0 1 0 1 1 1 0 0 e e P2.6 0 0 0 0 1 1 1 0 0 0 P3.7 0 1 1 1 1 0 0 1 0 1 P3.6 0 1 1 0 1 0 1 0 1 0 P3.3 X X X X X X X 0 1 X
NOTES: 1. `0' = Valid LOW for that pin, `1' = valid HIGH for that pin. 2. VPP = 12.75 V 0.25 V. 3. VCC = 5 V10 % during programming and verification. 4. Bit is output on P0.4 (1 = 12x, 0 = 6x). 5. Security bit one is output on P0.7. Security bit two is output on P0.6. Security bit three is output on P0.3. * ALE/PROG receives 5 programming pulses for code data (also for user array; 5 pulses for encryption or security bits) while VPP is held at 12.75 V. Each programming pulse is LOW for 100 s (10 s) and HIGH for a minimum of 10 s.
Table 16. Program Security Bits for EPROM Devices
PROGRAM LOCK BITS1, 2 SB1 1 2 U P SB2 U U SB3 U U PROTECTION DESCRIPTION No Program Security features enabled. (Code verify will still be encrypted by the Encryption Array if programmed.) MOVC instructions executed from external program memory are disabled from fetching code bytes from internal memory, EA is sampled and latched on Reset, and further programming of the EPROM is disabled. Same as 2, also verify is disabled. Same as 3, external execution is disabled. Internal data RAM is not accessible.
3 4
P P
P P
U P
NOTES: 1. P - programmed. U - unprogrammed. 2. Any other combination of the security bits is not defined.
2004 Apr 20
80
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
+5V
A0-A7 1 1 1
P1 RST P3.6 P3.7 OTP XTAL2
VCC P0 PGM DATA +12.75V 5 PULSES TO GROUND 0 1 0 A8-A13
EA/VPP ALE/PROG PSEN P2.7 P2.6
4-6MHz XTAL1 A8-A15 are programming addresses (not external memory addresses per device pin out) VSS
P2.0-P2.5
SU01746
Figure 55. Programming Configuration
5 PULSES 1 ALE/PROG: 0 1 2 3 4 5
SEE EXPLODED VIEW BELOW tGHGL = 10s MIN tGLGH = 100s10s 1 ALE/PROG: 0 1
SU00875
Figure 56. PROG Waveform
+5V
VCC A0-A7 1 1 1 P1 RST P3.6 P3.7 OTP XTAL2 4-6MHz XTAL1 A8-A15 are programming addresses (not external memory addresses per device pin out) VSS ALE/PROG PSEN P2.7 P2.6 P2.0-P2.5 P0 PGM DATA 1 1 0 0 ENABLE 0 A8-A13
EA/VPP
SU01747
Figure 57. Program Verification
2004 Apr 20
81
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
EPROM PROGRAMMING AND VERIFICATION CHARACTERISTICS
Tamb = 21C to +27C, VCC = 5 V 10 %, VSS = 0 V (See Figure 58) SYMBOL VPP IPP 1/tCLCL tAVGL tGHAX tDVGL tGHDX tEHSH tSHGL tGHSL tGLGH tAVQV tELQZ tEHQZ tGHGL NOTE: 1. Not tested. Programming supply voltage Programming supply current Oscillator frequency Address setup to PROG LOW Address hold after PROG Data setup to PROG LOW Data hold after PROG P2.7 (ENABLE) HIGH to VPP VPP setup to PROG LOW VPP hold after PROG PROG width Address to data valid ENABLE LOW to data valid Data float after ENABLE PROG HIGH to PROG LOW 0 10 4 48tCLCL 48tCLCL 48tCLCL 48tCLCL 48tCLCL 10 10 90 110 48tCLCL 48tCLCL 48tCLCL s s s s PARAMETER MIN 12.5 MAX 13.0 50 6
1
UNIT V mA MHz
PROGRAMMING* P1.0-P1.7 P2.0-P2.5 P3.4 (A0 - A14) ADDRESS
VERIFICATION* ADDRESS
tAVQV
DATA IN DATA OUT
PORT 0 P0.0 - P0.7 (D0 - D7)
tDVGL tAVGL
ALE/PROG
tGHDX tGHAX
tGLGH tSHGL
tGHGL tGHSL
LOGIC 1 EA/VPP LOGIC 0
LOGIC 1
tEHSH
P2.7 **
tELQV
tEHQZ
SU00871
NOTES: * FOR PROGRAMMING CONFIGURATION SEE FIGURE 55.
FOR VERIFICATION CONDITIONS SEE FIGURE 57. ** SEE TABLE 15.
Figure 58. EPROM Programming and Verification
2004 Apr 20
82
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
MASK ROM DEVICES Security Bits
With none of the security bits programmed the code in the program memory can be verified. If the encryption table is programmed, the code will be encrypted when verified. When only security bit 1 (see Table 17) is programmed, MOVC instructions executed from external program memory are disabled from fetching code bytes from the internal memory, EA is latched on Reset and all further programming of the EPROM is disabled. When security bits 1 and 2 are programmed, in addition to the above, verify mode is disabled.
Encryption Array
64 bytes of encryption array are initially unprogrammed (all 1s).
Table 17. Program Security Bits
PROGRAM LOCK BITS1, 2 SB1 1 2 U P SB2 U U PROTECTION DESCRIPTION No Program Security features enabled. (Code verify will still be encrypted by the Encryption Array if programmed.) MOVC instructions executed from external program memory are disabled from fetching code bytes from internal memory, EA is sampled and latched on Reset, and further programming of the EPROM is disabled.
NOTES: 1. P - programmed. U - unprogrammed. 2. Any other combination of the security bits is not defined.
2004 Apr 20
83
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
ROM CODE SUBMISSION FOR 16K ROM DEVICES
When submitting ROM code for the 16K ROM devices, the following must be specified: 1. 16 kbyte user ROM data 2. 64 byte ROM encryption key 3. ROM security bits. ADDRESS 0000H to 3FFFH 4000H to 403FH 4040H CONTENT DATA KEY SEC BIT(S) 7:0 7:0 0 COMMENT User ROM Data ROM Encryption Key FFH = no encryption ROM Security Bit 1 0 = enable security 1 = disable security ROM Security Bit 2 0 = enable security 1 = disable security
4040H
SEC
1
Security Bit 1: When programmed, this bit has two effects on masked ROM parts: 1. External MOVC is disabled, and 2. EA is latched on Reset. Security Bit 2: When programmed, this bit inhibits Verify User ROM. NOTE: Security Bit 2 cannot be enabled unless Security Bit 1 is enabled.
If the ROM Code file does not include the options, the following information must be included with the ROM code. For each of the following, check the appropriate box, and send to Philips along with the code: Security Bit #1: Security Bit #2: Encryption:
V V V
Enabled Enabled No
V V V
Disabled Disabled Yes If Yes, must send key file.
2004 Apr 20
84
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
PLCC44: plastic leaded chip carrier; 44 leads
SOT187-2
2004 Apr 20
85
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
LQFP44: plastic low profile quad flat package; 44 leads; body 10 x 10 x 1.4 mm
SOT389-1
2004 Apr 20
86
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
REVISION HISTORY
Rev _2 Date 20040420 Description Product data (9397 750 13173)
* Update Special Function Registers table. * Remove P3.4 from Figures 55 and 57.
_1 20030213 Product data (9397 750 10814)
Modifications:
2004 Apr 20
87
Philips Semiconductors
Product data
80C51 8-bit microcontroller family 16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz)
P83C654X2/P87C654X2
Purchase of Philips I2C components conveys a license under the Philips' I2C patent to use the components in the I2C system provided the system conforms to the I2C specifications defined by Philips. This specification can be ordered using the code 9398 393 40011.
Data sheet status
Level
I
Data sheet status [1]
Objective data
Product status [2] [3]
Development
Definitions
This data sheet contains data from the objective specification for product development. Philips Semiconductors reserves the right to change the specification in any manner without notice. This data sheet contains data from the preliminary specification. Supplementary data will be published at a later date. Philips Semiconductors reserves the right to change the specification without notice, in order to improve the design and supply the best possible product. This data sheet contains data from the product specification. Philips Semiconductors reserves the right to make changes at any time in order to improve the design, manufacturing and supply. Relevant changes will be communicated via a Customer Product/Process Change Notification (CPCN).
II
Preliminary data
Qualification
III
Product data
Production
[1] Please consult the most recently issued data sheet before initiating or completing a design. [2] The product status of the device(s) described in this data sheet may have changed since this data sheet was published. The latest information is available on the Internet at URL http://www.semiconductors.philips.com. [3] For data sheets describing multiple type numbers, the highest-level product status determines the data sheet status.
Definitions
Short-form specification -- The data in a short-form specification is extracted from a full data sheet with the same type number and title. For detailed information see the relevant data sheet or data handbook. Limiting values definition -- Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 60134). Stress above one or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability. Application information -- Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or modification.
Disclaimers
Life support -- These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application. Right to make changes -- Philips Semiconductors reserves the right to make changes in the products--including circuits, standard cells, and/or software--described or contained herein in order to improve design and/or performance. When the product is in full production (status `Production'), relevant changes will be communicated via a Customer Product/Process Change Notification (CPCN). Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless otherwise specified.
Contact information
For additional information please visit http://www.semiconductors.philips.com. Fax: +31 40 27 24825
(c) Koninklijke Philips Electronics N.V. 2004 All rights reserved. Printed in U.S.A. Date of release: 04-04
For sales offices addresses send e-mail to: sales.addresses@www.semiconductors.philips.com.
Document order number:
9397 750 13173
Philips Semiconductors
2004 Apr 20 88

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